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A top

abdomen (say: AB-doh-min) = the part of the body between the ribs and pelvis that holds the stomach, intestines, liver, and other organs.

abstinence (say: AB-stuh-nuhns) = not having sex of any kind.

acne (say: AK-nee) = pimples on the skin often caused by hormone changes during puberty.

acquired immunodeficiency syndrome (say: uh-KWEYE-urd IH-myoo-noh-dih-FISH-uhn-see SIN-drohm) (AIDS) = a disease that hurts the immune system, so that it becomes easy to get dangerous infections and cancers. It is caused by HIV infection. Learn more about HIV and AIDS.

acupuncture (say: AK-yoo-punk-shur) = a kind of alternative medicine in which thin needles are stuck into the skin at certain points on the body to help control pain or other symptoms.

addiction (say: uh-DIK-shuhn) = an illness in which you become dependent on, or can't do without, certain physical substances or an activity. When a person is addicted to something, they cannot control or stop their urges. Substances you can be addicted to include tobacco, alcohol, and drugs (both illegal and prescription medicine). Activities that can be addicting include lying, stealing, cutting, and gambling. Addiction can be treated with counseling and, in some cases, medication.

adhd(say: ADHD) = attention deficit hyperactivity disorder

adolescence (say: ad-uhl-ESS-uhns) = the period of life from puberty to adulthood when a young person "grows up."

adrenal gland (say: uh-DREE-nuhl gland) = one of a pair of small glands, each of which sits on top of the kidneys. These glands produce hormones that help to control the body's heart rate, blood pressure, the way food gets used, and other functions. They make the hormone adrenaline, which the body releases in response to stress.

aerobic exercise (say: air-OH-bik EK-sur-syz) = a type of physical activity that burns fat, gets your heart rate going (you will be able to feel it beating faster), and makes your heart muscle stronger. It also increases the number of blood cells you have, which helps your blood carry more needed oxygen to blood vessels throughout your body. An example of aerobic exercise is jogging or swimming.

age of consent (say: ayj uhv kuhn-SENT ) = the minimum age for marrying and sexual contact (varies from state to state).

AIDS (say: ayds) = see acquired immunodeficiency syndrome.

albinism (say: AL-buh-niz-uhm) = a group of conditions that cause a problem with your body's ability to make melanin, which is the pigment (color) of your skin, hair, and eyes. This can make the skin and hair look very white.

alcoholic (say: al-kuh-HOL-ic) = someone who is addicted to alcohol. See alcoholism.

alcoholism (say: al-kuh-hol-ism) = alcoholism means that someone often drinks too much alcohol (such as beer, wine, or liquor) and can't stop.

allergies(say: AL-ur-jee) = a sensitivity to things that are usually not harmful, such as certain foods or animals. When a person is exposed to an allergen (something she or he is allergic to), the person’s immune system gives off a much bigger response than it normally would. The result is to have a reaction, such as sneezing, hives, or trouble breathing.

amenorrhea (say: ay-men-uh-REE-uh) = when a woman does not have periods either ever (after age 16) or when periods stop as a result of pregnancy, too much exercise, extreme obesity or not enough body fat, or emotional distress.

amniotic fluid (say: AM-nee-ah-tic FLOO-id) = clear, yellowish liquid that surrounds an unborn baby during pregnancy.

amputate (say: AM-pyoo-tate) = when a limb (such as an arm or a leg) or another body part is cut off because of a severe injury or infection.

anaerobic exercise (say: AN-uh-ROH-bik EK-sur-syz) = physical activity that involves building muscle strength. This type of exercise goes along well with aerobic exercise because having stronger muscles helps you to burn more calories. This will also help you look toned and feel strong. An example of anaerobic exercise is lifting weights.

analgesic (say: an-uhl-JEE-zik) = medicine used to relieve pain. These pain relievers don't get rid of what causes the pain; rather, they block the nerve pathways that send pain signals from the body part to the brain so that you don't hurt as much.

anal sex (say: AYN-uhl seks) = sex that involves putting the penis in the anus, or butt.

anemia (say: uh-NEE-mee-uh) = when the total amount of red blood cells or hemoglobin is below normal. Anemia can cause severe fatigue and other health problems. There are many different types of anemia.

anesthesia (say: ah-nus-THEE-zhuh) = a drug that makes you sleepy or can numb a part of your body before surgery so that you don't feel pain.

anorexia nervosa (say: AN-uh-REK-see-uh nur-VOH-suh) = an illness in which people don't eat enough and therefore can't stay at a healthy body weight. People with anorexia have a fear of gaining weight and sometimes think they are heavier than they really are. Anorexia nervosa can result in life-threatening weight loss and amenorrhea.

antibiotic (say: AN-teye-beye-OT-ihk) = medicine used to fight bacterial infections by killing bacteria or stopping it from growing. Antibiotics can help your body's immune system fight off infections. If you have ever had strep throat, your doctor probably gave you an antibiotic to take.

antibody (say: ANT-uh-bod-ee) = any of a large number of proteins produced by white blood cells to fight bacteria, viruses, and other foreign substances.

antibody rheumatoid factor (say: ANT-uh-bod-ee ROO-mah-toyd FAC-tor) = a part of the blood that shows if a person has rheumatoid arthritis or juvenile rheumatoid arthritis.

antidepressant (say: ANT-ee-dee-PRESS-ant) = drugs given by your doctor to treat depression.

antigens (say: ANT-ih-gens) = germs that enter the body and cause the immune system to respond.

antiperspirant (say: ANT-uh-PUR-spuh-ruhnt) = a substance applied to the skin to help prevent sweating and body odor.

antiretroviral drugs (say: ANT-ee-re-troh-vye-ral druhgs) = drugs that stop HIV or other types of retroviruses from increasing in the body.

anus (say: AY-nuhs) = opening between the buttocks through which solid waste leaves the body.

artery (say: ART-uh-ree) = any of the thick-walled blood vessels that carry blood away from the heart to other parts of the body.

asphyxiation (say: as-FIK-see-AY-shuhn) = when a person can't get oxygen to breathe.

asthma (say: AZ-muh) = a lung disorder that affects your airways. When the airways are inflamed, a person may wheeze, feel short of breath, cough, and feel tightness in the chest.

Attention Deficit Hyperactivity Disorder(say: uh-TEN-chuhn DEF-uh-sit HEYE-pur-ak-TIV-uht-ee diss-OR-dur) = 

a behavioral condition that makes it hard for people to pay attention and concentrate.

autism (say: AW-tiz-uhm) = a disorder in the brain that affects both verbal and nonverbal communication (speaking and non-speaking) skills. The main signs and symptoms of autism involve communication, social interactions, and repetitive behaviors. It is a "spectrum" disorder, which means people with autism can have different symptoms that vary from mild to severe.

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bacterial vaginosis (say: bak-TEER-ee-uhl vaj-uh-NOH-suhss) = an infection of the vagina in which the normal balance of bacteria in the vagina is changed so that there are more "harmful" bacteria and fewer "good" bacteria.

behavioral therapy (say: bee-HAYV-yor-uhl THEH-rup-ee) = a kind of therapy used by a psychologist or a psychiatrist that helps people to change the way they behave and act.

binge eating disorder (say: binj EET-eeng diss-ORD-ur) = a condition marked by periods of out-of-control eating. Unlike bulimia nervosa, binge eating disorder usually does not involve purging (throwing up or doing other things to get rid of the food).

biopsy (say: BYE-op-see) = when a doctor takes a very small piece of your body, such as some skin, to look at under a microscope.

bipolar disorder (say: bye-POH-lar diss-ORD-ur) = a mental illness that causes changes in a person's mood and energy. It causes mood swings -- from very "high," or manic, moods to very sad and hopeless moods.

birth control pill (say: BURTH CUN-troll pill) = a kind of medicine that women can take daily to prevent pregnancy. It is sometimes called "the Pill" or oral contraception.

birth defect (say: BURTH duh-FEHCT) = a problem that happens while a baby is forming in the mother's body. Most birth defects happen during the first three months of pregnancy and may affect how the baby's body looks, works, or both.

bladder (say: BLAD-dur) = this organ holds urine. It is in the lower part of your abdomen.

blood glucose level (say: bluhd GLOO-cohs LEV-uhl) = the amount of glucose in the blood. Glucose is a sugar from the food we eat and gives us energy. Too much glucose in the blood for a long time can cause diabetes and hurt some parts of the body, like the heart and kidneys.

blood pressure (say: bluhd PRESH-ur) = as blood is pumped from your heart through your body, the blood exerts force or pressure against the blood vessel walls. Your blood pressure reading is a measure of this pressure. When that reading goes above a certain point, it is called high blood pressure or hypertension. Changes in lifestyle, healthy eating, and medicine can lower high blood pressure.

blood test (say: bluhd test) = this is either done by using a finger prick to get a few drops or by inserting a needle into a vein to get a larger amount of blood. Blood tests are used to check for many different diseases and viruses.

blood vessel (say: bluhd VES-sul) = a tube-shaped part of the circulatory system which helps blood move through the body.

body language (say: BOD-ee layng-gwij) = a way of saying something without using words.

bone marrow (say: bohn MAIR-oh) = soft tissue found inside bones from which blood cells are produced and released into the bloodstream.

bulimia nervosa (say: byoo-LEE-mee-uh nur-VOH-suh) = an illness defined by uncontrollable overeating, usually followed by making oneself throw up or purge (get rid of food) in other ways.

BV (say: B-V) = see bacterial vaginosis.

C top

calorie (say: KAL-uh-ree) = when talking about food, a calorie is a measure of the amount of energy you get from eating a certain amount of food. When talking about physical activity, a calorie is a measure of the energy that your body uses in performing the activity.

cancer (say: KAN-sur) = when cells that are not normal develop and multiply. There are at least 200 different kinds of cancers, which can grow in almost any organ of the body.

capillary (say: KAP-uh-lair-ee) = any of the tiny blood vessels that branch through body tissues to deliver oxygen and nutrients and carry away waste products.

carbohydrate (say: KAR-bo-hye-DRAYTE) = one of the three main nutrients in food that is the body's main source of energy.

carbon dioxide (say: KAR-buhn deye-OK-syd) = a body waste product that is a colorless and odorless gas.

carcinogen (say: KAR-sin-oh-gin) = any substance that causes cancer.

celiac disease (say: SEE-lee-ak diz-EEZ) = when the small intestine is hurt from eating gluten and other substances like it (gluten intolerance). Glutens are found in wheat, rye, oats, barley, and other grains.

cerebral palsy (say: suh-REE-bruhl POL-zee) = when injuries to the brain cause damage to the nerves and loss of movement. The injuries happen while a baby is growing in the womb or near the time the baby is born.

cervix (say: SUR-viks) = the narrow entryway between the vagina and the uterus. The muscles of the cervix are flexible so that it can expand to let a baby pass through when he or she is being born.

cesarian(say: sez-AIR-ee-ahn SEC-shun) = when a baby is born by an operation in which the doctor cuts open the mother’s abdomen.

chemotherapy (say: KEE-moh-THAIR-uh-pee) = medicines used to treat cancer. Since cancer cells tend to divide very fast, chemotherapy works by getting in the way of these cells dividing and trying to stop the cancer from spreading. Sometimes chemotherapy can cure the disease by helping to get rid of all the cancer cells in the body. Also called chemo.

chlamydia (say: kluh-MID-ee-uh) = a common sexually transmitted infection that often has no symptoms. Untreated, chlamydia can lead to pelvic infection and infertility (not able to become pregnant). People who are sexually active and who have multiple sexual partners are at the highest risk of getting chlamydia. A doctor can test and treat people for chlamydia. Learn more about this STI.

cholesterol (say: koh-LESS-tur-awl) = a soft, waxy substance that is present in all parts of the body. It helps make cell membranes, some hormones, and vitamin D. The liver makes all the cholesterol the human body needs. So eating too much from animal foods like meats and whole milk dairy products can make your cholesterol go up, which can lead to health problems.

chronic disease or illness (say: KRON-ihk diz-EESE) = a sickness that lasts over a long period of time, perhaps your whole life.

chronic fatigue syndrome (say: KRON-ihk fuh-TEEG SIN-drohm) = a very severe and long-term feeling of weakness and being tired, even after getting rest.

circulatory system (say: SUR-kyuh-luh-TOR-ee SISS-tuhm) = the heart, the blood, and the system of blood vessels that moves blood through the body.

cleft lip or palate (say: kleft lip or PAL-uht) = a defect of the lip and/or roof of the mouth that happens before a baby is born. This can affect the way the lip looks and also cause problems feeding as an infant and learning to speak.

clique (say: klik) = a close group of friends that is exclusive; not all people who would like to join are accepted. Members of cliques share similar interests and goals. Cliques can be seen as powerful, often including the most popular kids and attracting attention from classmates. To gain power, clique leaders often switch back and forth between making their "followers" -- clique members -- feel good and then cutting them down. Read more about cliques.

clitoris (say: CLIT-or-us) = a female sex organ located near the top of the vagina.

clotting (say: KLOT-eeng) = the process by which the body forms a plug to seal damaged blood vessels and stop bleeding.

condom (say: KON-duhm) = a type of birth control used to prevent pregnancy and the spread of some sexually transmitted infections (STIs). The male condom is a thin rubber-like sheath put on the penis before sex. The female condom is a pouch put into the vagina before sex to prevent pregnancy.

crabs (say: ) = see pubic lice.

crush (say: krush) = a short-lived or temporary fascination with someone.

culture test (say: KUHL-chur test) = samples of body tissue are taken from an infected area of your body. These samples are used to find out what is causing an infection.

cystic fibrosis (say: SISS-tik feye-BROH-suhss) = a disease that causes both breathing and digestion problems. Cystic fibrosis can be inherited, or passed down in a family's genes.

D top

dandruff (say: DAN-druff) = flakes of skin on your head that can be seen and come loose onto your hair or clothes.

date rape (say: dayt rayp) = when you are forced to have sex by someone you know.

defensive (say: dih-FEN-siv) = being ready to react to others' comments in a way that protects your ego. Denial and blaming are examples of defensive reactions.

dehydration (say: dee-hie-DRAY-shun) = when the body does not have enough water to work properly. Signs of dehydration are thirst, a dry mouth, tiredness, feeling dizzy, dark-colored urine, or very little urine at all.

deodorant (say: dee-OHD-uh-ruhnt) = a substance applied to the skin that covers up or takes away body odor, such as from under the arm.

depilatory (say: dih-PIL-uh-tor-ee) = a cream used to remove unwanted hair.

depression (say: dih-PRESH-uhn) = an illness that involves the body, mood, and thoughts. It affects the way a person functions, eats and sleeps, feels about herself, and thinks about things. It is more than just feeling "down in the dumps" or "blue" for a short time. It is not a sign of personal weakness or a condition that can be willed or wished away. Depression can be treated with counseling and medicine.

diabetes (say: deye-uh-BEET-eez) = a disease in which your blood sugar levels are above normal. With type 1 diabetes, the body does not make enough insulin, which is the chemical that controls blood sugar levels. With type 2 diabetes, the body does not use insulin properly, and then over time, loses the ability to make enough insulin. Type 2 diabetes is the most common type and can be prevented with physical activity and healthy eating.

dietitian (say: deye-uh-TISH-uhn) = a person who is an expert in nutrition.

discrimination (say: dys-crim-ihn-A-shun) = when a person is treated unfairly because of his or her sex or race.

douching (say: DOO-sheeng) = rinsing or cleaning out the vagina, usually with a prepackaged mix of fluids. The fluid is in a bottle and squirted into the vagina through tubing and a nozzle. Doctors do not suggest douching to clean the vagina. Douching changes the delicate chemical balance in the vagina, which can make a woman more prone to infections.

Down syndrome (say: down SIN-drohm) = when an extra copy of chromosome 21 is present when a baby develops. (A chromosome holds a cell's genetic information for a person.) The extra chromosome usually causes mental and physical development to be slower in people with Down syndrome. They may also have other related health problems.

drug abuse(say: druhg uh-BYOOSS) = 

the use of a drug not for medical reasons but to change one's mental state.

drug dependence (say: druhg dih-PEN-duhns) = an addiction to drugs, or the inability to stop using harmful substances despite the harmful problems they cause. See addiction.

dysmenorrhea (say: diss-men-uh-REE-uh) = painful menstrual periods that can also go along with nausea and vomiting and either constipation or diarrhea. Dysmenorrhea is common among teenagers.

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eating disorder (say: EET-eeng diss-ORD-ur) = an illness that involves serious problems with normal eating behaviors, such as feelings of distress and concern about body shape or weight, severe overeating, or starving oneself. Anorexia nervosa, bulimia nervosa, and binge eating disorder are types of eating disorders.

ectopic pregnancy (say: ek-TOP-ihk PREG-nuhn-see) = when a fertilized egg implants outside the uterus, usually in the fallopian tubes.

eczema (say: EK-zeh-muh) = a skin irritation that causes the skin to be red, itchy and dry. It can be caused by allergies.

ejaculation (say: ih-JAK-yuh-LAY-shuhn) = the release of semen (whitish fluid that contains sperm) from a man's penis.

electrolysis (say: ih-lek-TROL-uh-suhss) = when an electrical current is used to remove unwanted hair from the body.

emphysema (say: em-fuh-ZEE-muh) = a disease than involves damage to the air sacs (alveoli) in the lungs. The air sacs have trouble deflating once filled with air, so they are unable to fill up again with the fresh air needed to supply the body. Cigarette smoking is the most common cause of emphysema.

endometrial hyperplasia (say: EN-doh-MEE-tree-uhl heye-pur-PLAY-zhuh) = a thickening of the lining of the uterus with the finding of abnormal cells -- a precancerous condition.

endometriosis (say: EN-doh-MEE-tree-OH-suhss) = a condition where tissue that normally lines the uterus grows in other areas of the body. This can cause pain, irregular menstrual bleeding, and infertility for some women.

endometrium (say: EN-doh-MEE-tree-uhm) = the lining of the uterus.

endurance (say: en-DUR-uhns) = the measure of your body's ability to keep up an activity without getting tired. The more endurance you have, the longer you can swim, bike, run, or play a sport before tiring out.

enriched (say: en-RICHT) = when vitamins or minerals are added to a food to make it more nutritious. An example is calcium-enriched orange juice.

epilepsy (say: EP-uh-lep-see) = a brain disorder that causes seizures, which are out of control body movements.

erythrocyte (say: ih-RITH-ruh-syt) = a mature red blood cell.

estrogen (say: ESS-truh-juhn) = a female hormone made by the ovaries. Estrogen plays important roles in puberty, the menstrual cycle, and in reproduction.

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fallopian tube (say: fuh-LOH-pee-uhn toob) = one of a pair of organs that connect the ovaries to the uterus. There is a fallopian tube on each side of the uterus. When one of the ovaries releases an egg, it travels through the fallopian tube toward the uterus. Fertilization (when a man's sperm and a woman's egg join together) usually happens in the fallopian tube.

flirt (say: flurt) = to show a casual attraction or interest in someone.

folate or folic acid (say: FOL-ihk ASS-ihd) = an important B vitamin used in the body to make new cells. Girls who are sexually active should get enough folic acid to lower the risk of some birth defects, such as spina bifida, should pregnancy occur. Taking a folic acid pill is the best and easiest way to be sure you are getting enough.

fortified (say: FORT-uh-fyd) = when ingredients are added to foods or drinks to either make them taste better or add nutrients. An example is breakfast cereal fortified with vitamins.

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gene (say: jeen) = a gene is the basic unit of heredity in a living thing. Genes are in all body cells. Genes come from both parents and are responsible for the features that are passed down in your family, such as eye and hair color.

genital area (say: JEN-uh-tuhl AIR-ee-uh) = the area around the vagina, penis, scrotum, anus, and thigh.

genital herpes (say: JEN-uh-tuhl HUR-peez) = a sexually transmitted infection (STI) caused by the herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2). Learn more about this STI.

gingivitis (say: jin-juh-VYT-uhss) = inflammation of the gums; the first stage of gum disease. Gingivitis is caused by plaque deposits, which are made up of bacteria, mucus, and food debris. Injury to the gums from harsh brushing or flossing can also cause inflammation.

glands(say: glands) = a cell, group of cells, or organ that makes chemicals and releases them for use by other parts of the body or to be excreted. The pituitary gland, for example, makes growth hormone, which stimulates cells to grow and divide. Sweat glands excrete water, salts, and waste to help cool down the body.

glucose(say: GLOO-kohs) = a sugar found in the blood that comes from food and provides fuel to the body.

gonorrhea (say: GON-uh-REE-uh) = a sexually transmitted infection (STI) caused by bacteria that can grow and multiply easily in the warm, moist areas of the reproductive tract, including the cervix, uterus, urethra, and fallopian tubes. Learn more about this STI.

granulocyte (say: GRAN-yuh-loh-syt) = a type of white blood cell that helps the body prevent and fight infections caused by bacteria.

gum disease (say: GUHM DIZ-eaze) = an infection of the skin that holds your teeth in place.

gynecological examination (say: GYN-uh-kuh-LOJ-uh-kuhl ig-ZAM-uh-NAY-shuhn) = when a doctor checks inside the vagina to make sure organs are healthy.

gynecologist (say: GYN-uh-KOL-uh-juhst) = a doctor who has special training in caring for a women's reproductive organs and system.

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halitosis (say: hal-lih-TOH-suhss) = bad-smelling breath.

hazing (say: HAY-zeeng) = a humiliating or degrading act expected of someone joining a group. It may cause physical or emotional harm, even if the person wants to participate. Hazing occurs with sports teams, social groups, and fraternities or sororities. Some examples of hazing are: being forced to wear embarrassing or humiliating clothing in public; being forced to drink alcohol or other bad substances; and being sworn at or insulted. Read more about hazing.

heart disease (say: hart diz-EEZ) = a number of abnormal conditions affecting the heart and the blood vessels in the heart. Coronary artery disease is the most common type of heart disease. It involves a gradual buildup of plaque in the coronary artery, the blood vessel that brings blood to the heart. When this happens, the heart doesn't get enough blood to work properly.

hemoglobin (say: HEE-muh-gloh-buhn) = a substance containing iron found in red blood cells, which helps the blood carry and deliver oxygen to body tissues.

hemophilia (say: HEE-muh-FILL-ee-uh) = an inherited disease that makes it difficult for the blood to clot, which is how the blood sticks together to stop flowing. Without clots, a simple cut can cause someone to lose a dangerous amount of blood. It affects mostly boys.

hepatitis (say: hep-uh-TYT-uhss) = inflammation of the liver caused by infections from bacteria, viruses, or toxins such as alcohol or drugs. There are different types of hepatitis, including hepatitis A, B, C, and autoimmune hepatitis. Read our information on hepatitis B.

herbal supplement (say: UR-buhl SUHP-luh-muhnt) = any of a variety of natural products, such as teas, pills, or creams, that are used as medicine. There has not been a lot of research done on herbal supplements to really know how well they work or how safe they are. It is important that you ask your doctor before using anything that he or she has not given you.

heredity (say: her-ED-it-ee) = the passing of traits to children from parents or ancestors. Traits may be physical, such as hair color, or they may be behavioral. Traits are passed through genes.

herpes (say: HUR-peez) = see genital herpes.

HIV (say: H-I-V) = see human immunodeficiency virus.

hives (say: HYVES) = red and sometimes itchy bumps on the skin. They are usually caused by an allergic reaction to a drug or food.

Hodgkin's lymphoma (say: HOJ-kinz lim-FOH-muh) = a type of cancer that affects the tissue found in lymph nodes (glands that protect the fluids in your body), the spleen, the liver, and bone marrow.

homicide (say: HOM-uh-syd) = the killing of one person by another. Homicide is not legal and is a punishable crime.

hormone (say: HOR-mohn) = a natural body chemical, such as estrogen, that has effects on or controls other parts of the body. Manmade hormones, such as birth control pills, are drugs similar to human hormones.

HPV (say: H-P-V) = see human papillomavirus.

HPV test (say: H-P-V test) = a test done on a sample of cells collected from the cervix to look for human papillomavirus (HPV), the virus that can cause cervical cancer. The test may find HPV before there are cell changes to the cervix. Learn more about HPV.

HPV vaccine (say: H-P-V vak-SEEN) = a vaccine to help prevent infection with the human papillomavirus, (HPV). Learn more about HPV.

human immunodeficiency virus (say: HYOO-muhn IH-myoo-noh-di-FISH-uhn-see VI-ruhs) = a virus that damages the immune system. This makes it hard for your body to fight infections. People who are infected with HIV may not have any symptoms for more than 10 years, but they can still give it to others. A person can get HIV through unprotected vaginal, oral, and anal sex and through shared needles, such as those for drug use and tattoos. A baby can get HIV from its mother during pregnancy, birth, and breastfeeding. HIV can lead to AIDS. Learn more about HIV and AIDS.

human papillomavirus (say: HYOO-muhn pap-ah-LO-mah-VI-ruhs ) = a sexually transmitted infection (STI) that can cause genital warts or cell changes in the cervix that can lead to cancer. HPV infection is the main cause of most cervical cancers. Regular Pap tests or HPV tests can find cell changes in the cervix early so the cervix can be treated before the cells turn into cancer. A new HPV vaccine for girls and young women can prevent HPV infection. Learn more about HPV.

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immune system (say: ih-MYOON SISS-tuhm) = the system that protects the body against infection and foreign substances. The immune system works to seek out, identify, and kill invaders such as bacteria or tumor cells.

immunization (say: ih-myoo-nuh-ZAY-shuhn) = treatment that protects your body against infection from certain diseases, such as the measles, whooping cough, and chicken pox. Most immunizations are given by a shot. The shot contains germs that have been killed or weakened, which triggers the body's immune system to develop the ability to fight off an infection from these germs.

infected (say: in-FEK-tuhd) = to have a disease or virus.

infertility (say: in-fur-TIL-uh-tee) = when a couple has problems getting pregnant after one year of regular sexual intercourse without using any birth control methods. If a woman keeps having miscarriages (pregnancy loss), it is also called infertility. Infertility can be present in either a man or a woman.

insulin (say: IN-suh-lin) = a hormone that helps glucose, a type of sugar from food, get into cells for energy. Some people with diabetes do not make enough insulin to break down the sugar in food.

intestines (say: in-TES-tines) = the long, tube-shaped organ in the abdomen that digests food. The intestine has two parts, the small intestine and the large intestine.

K top

kidneys (say: KID-neez) = two organs that clean waste out of the blood and make hormones.

L top

lactose intolerance (say: LACK-tohse in-TAH-lur-ans) = when the body cannot digest lactose. Lactose is a kind of sugar found in milk and dairy products such as cheese or ice cream.

lean (say: leen) = meat and poultry that has little or no fat, making it healthier to eat.

legume (say: LAYG-yoom) = a seed or pod of a certain kind of plant that is used as food. Legumes include beans, peas, lentils, and peanuts.

leukemia (say: loo-KEE-me-uh) = a kind of cancer that starts in the bone marrow. It causes a high number of blood cells to form.

leukocyte (say: LOO-kuh-syt) = a white blood cell that is part of the immune system. It defends the body against infections.

ligament (say: LIG-uh-muhnt) = a tough band of tissue that connects bones to each other.

lupus (say: LOO-puhss) = one of a type of chronic diseases that causes the immune system to attack healthy tissues in the body. Lupus can affect many body parts including joints, skin, the heart, lungs, kidneys, and the nervous system.

lymph node (say: limf nohd) = one of a network of vessels that contain white blood cells to help fight infection. Also called lymph gland.

lymphocyte (say: LIM-fuh-syt) = a white blood cell in the immune system that produces antibodies.

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malnourished (say: mal-NUR-isht) = when a body does not get the proper nutrition it needs to work.

marijuana (say: mair-uh-WAWN-uh) = an illegal drug that comes from a type of hemp plant. It is a green or gray mixture of dried leaves and other parts of the plant. Marijuana can be smoked or eaten in food. It can contain over 400 chemicals, but the main active chemical in marijuana is THC.

measles (say: MEE-zels) = a disease that you can catch from someone else with fever, cough, and red bumps on the skin. It is caused by a virus and usually happens to children.

mediation (say: mee-dee-AY-shuhn) = bringing in an outside person(s) to help end a conflict.

menarche (say: MEN-ar-kee) = the first menstrual period or beginning of menstruation.

meningitis (say: men-uhn-JYT-uhss) = a dangerous infection that affects the brain and spinal cord.

menopause(say: MEN-uh-pawz) = the normal change in a woman's life when her period stops and she can no longer become pregnant. A woman has reached menopause when she has not had a period for 12 months in a row. This happens for most women after age 45.

menstruation (say: MEN-stroo-AY-shuhn) = the blood flow from the uterus that happens about every 28 days in women of childbearing age who are not pregnant. Commonly called a woman's "period."

metabolism (say: muh-TAB-uh-liz-uhm) = the different ways that the body makes and uses energy, such as in digesting food.

moderate exercise (say: MOD-uh-ruht EK-sur-syz) = physical activity that involves a medium amount of energy and effort. One who is active at a moderateintensity level should be able to carry on a conversation comfortably while engaging in the activity. Fast walking is moderate exercise while running is vigorous exercise, which requires more energy and effort.

molestation (say: moh-less-TAY-shun) = when someone makes unwanted sexual advances toward you. See also sexual assault.

muscular dystrophy (say: MUHSS-kyuh-lur DISS-truh-fee) = a group of disorders that causes muscles to be weak and causes loss of muscle tissue.

mutual masturbation (say: MYOO-chuh-wuhl mas-tur-BAY-shuhn) = when two people touch each other's sex organs or genitals for sexual pleasure.

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obesity (say: oh-BEE-suh-tee) = having too much body fat. Obesity is more extreme than being overweight, which means weighing too much. Obesity is measured using body mass index (BMI). Calculate your BMI here.

occupational therapist (say: OK-yoo-PAY-shuhn-uhl THAIR-uh-puhst) = a health care specialist who helps people with a disability, illness, injury, or other health issue learn or relearn how to do daily activities like eating, dressing, or bathing.

oral contraceptive (say: OR-uhl con-trah-SEP-tiv) = See birth control pill.

oral sex (say: OR-uhl seks ) = sucking and/or licking a partner's sex organ.

osteoporosis (say: OSS-tee-oh-puh-ROH-suhss) = a disease that thins and weakens bones to the point where they break easily.

over-the-counter (say: OH-vur thuh KOWN-tur) = when you can buy a medicine without a prescription (a doctor's order). Examples include cold medicine, medicines for stomach pain, or pain relievers.

ovulation (say: ov-yoo-LAY-shuhn) = when an ovary releases an egg, about once each month, as part of the menstrual cycle.

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pancreas (say: PAN-cree-uhs) = a long, flat gland in your abdomen that makes enzymes important for digestion, including insulin.

Pap test (say: pap test) = a test done on a sample of cells collected from the cervix to look for cell changes that could be cancer or that could turn into cancer.

PCOS (say: P-C-O-S) = see polycystic ovary syndrome.

peer pressure (say: peer PRESH-ur) = social pressure on somebody to act or dress a certain way in order to be accepted as part of a group.

pelvic inflammatory disease (say: PEL-vihk-in-FLAM-uh-tor-ee diz-EEZ) = an infection of the female reproductive organs that are above the cervix, such as the uterus, fallopian tubes, or ovaries. It is the most common and serious problem caused by sexually transmitted infections (STIs). PID can cause ectopic pregnancy, infertility, chronic pelvic pain, and other serious problems. Symptoms can include fever, foul-smelling vaginal discharge, extreme pain, and vaginal bleeding.

penis (say: PEE-nuhss) = a male sex organ.

physical therapist (say: FIZ-ih-kuhl THAIR-uh-puhst) = a health care specialist who uses body movements to help treat injuries and other physical health issues.

PID (say: P-I-D) = see pelvic inflammatory disease.

pituitary gland (say: puh-TOO-uh-tair-ee gland) = a small gland attached to the brain that makes many important hormones, including growth hormone and hormones that control the onset of puberty, sexual development, and reproductive function. It also makes endorphins (en-DORF-uhns), special chemicals that help provide natural pain relief from within the body.

plaque (say: PLACK) = a buildup of materials on the walls of arteries or on teeth.

plasma (say: PLAZ-muh) = the liquid part of blood, which contains nutrients, proteins, minerals, and dissolved waste products.

platelet (say: PLAYT-luht) = any of the small cells in the blood that play a key role in blood clotting.

polycystic ovary syndrome (say: pol-ee-SISS-tik OH-vuh-ree SIN-drohm) = a mild imbalance of hormones that can cause irregular periods, unwanted hair growth, weight gain, and acne. This is a common condition that begins during the teenage years. Getting pregnant can be hard or impossible for women with PCOS. Learn more about PCOS.

preseminal fluid (say: pree-SEM-ihn-uhl FLOO-ihd) = the fluid that comes out of the penis before ejaculation of semen. There may be only a small amount of this fluid, but it still contains spermand can still pass sexually transmitted infections, including HIV. Also called "pre-ejaculate."

progesterone (say: proh-JESS-tuh-rohn) = a female hormone made by the ovaries. Progesterone plays important roles in puberty, the menstrual cycle, and in reproduction.

psychiatrist (say: suh-KYE-uh-trist) = a doctor who went to medical school for special training in the way people think and feel. A psychiatrist helps people who have troubles with their emotions, their feelings, or the way they act. A psychiatrist is a medical doctor and can order medicine.

psychologist (say: suh-KAH-loh-jist) = a person who went to school for special training in the way people think and feel. A psychologist helps people who have troubles with their emotions, their feelings, or the way they act. A psychologist uses talk therapy and cannot order medicine.

puberty (say: PYOO-burt-ee) = the process of developing from a child to sexual maturity, when a person becomes capable of having children. In a girl, puberty includes a growth spurt, development of breasts and hips, growth of body hair, and the beginning of menstruation (having periods).

pubic area (say: PYOO-bik AIR-ee-uh) = on and around the genitals.

pubic lice (say: PYOO-bik lys) = small parasites that feed on human blood. They are spread through sexual contact and attach themselves to the skin and hair in the pubic area. Learn more about this STI.

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red blood cell (say: red blud sel) = any of the small, hemoglobin-filled blood cells that carry oxygen to the body's tissues.

registered dietitian (say: REJ-uh-sturd deye-uh-TISH-uhn) = an expert on food health. In the United States, a registered dietician has taken certain coursework and passed a certification exam.

rehabilitation (say: ree-huh-bil-uh-TAY-shuhn) = training, therapy, or other help given to someone who has a serious injury or illness. This training will help him or her to live a healthy and productive life.

relaxation technique (say: ree-lak-SAY-shuhn tek-NEEK) = a process or skill to help you calm down, loosen up, and reduce stress. Examples include meditation (sitting still, breathing slowly, and clearing your mind), yoga, deep breathing, and visualization (closing your eyes and seeing a scene that clams you, such as a beach or a mountain lake).

reproductive organ (say: ree-proh-DUHK-tiv OR-guhn) = a body part involved in producing a baby. In a female, they include the uterus, ovaries, fallopian tubes, and vagina. In a male, they include the testicles and penis.

retrovirus (say: REH-troh-vye-russ) = retroviruses are known to lead to certain types of cancers in both people and animals. They can also cause infections. HIV, the virus that causes AIDS, is one kind of retrovirus.

rheumatoid arthritis (say: ROO-muh-toyd ar-THRYT-uhss) = a disease that causes pain and swelling in joints, tissues, and sometimes other parts of your body.

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scoliosis (say: skoh-lee-OH-suhss) = when the spine curves away from the middle of the body to the side.

seizures (say: SEE-zhures) = uncontrolled muscle movement caused by abnormal electrical activity in the brain.

self-esteem (say: self uh-STEEM) = how you feel about yourself. It includes how you feel about who you are, the way you act, and how you look. When a person does not think too highly of themselves, he or she is said to have low self-esteem. When a person accepts the way they look, act, and feel, they are said to have high self-esteem.

semen (say: SEE-muhn ) = whitish fluid containing sperm that comes out of the male's penis. Also known as "cum."

sexual assault (say: SEK-shuh-wuhl uh-SALT) = any type of sexual activity that you do not agree to, including touching you, forcing you to touch someone, and forcing a body part into your vagina, rectum (bottom), or mouth. Another term for this can be molestation (maw-luhss-TAY-shuhn).

sexual contact (say: SEK-shuh-wuhl KON-takt) = any type of touching during sexual activity between two people, including sexual intercourse, oral sex, and skin-to-skin contact in the genital area (around the vagina, penis, scrotum, anus, and thigh). Sexually transmitted infections (STIs) such as genital herpes, HPV (warts), and syphilis can be passed by having sexual contact with areas that are not covered by a condom.

sexual intercourse (say: SEK-shuh-wuhl INT-ur-kors) = when a man's penis is put into a woman's vagina.

sexually transmitted disease (say: SEK-suh-wuh-lee trans-MIT-uhd duh-ZEEZ, or STD) = see sexually transmitted infection.

sexually transmitted infection (say: SEK-shuh-wuh-lee trans-MIT-uhd ihn-FEK-shuhn) = infection that is spread from person to person through sexual contact. Also called sexually transmitted disease.

sickle cell anemia (say: SIK-uhl sel uh-NEE-mee-uh) = a condition that is passed down in a family's genes in which the red blood cells can become "C" shaped. This keeps them from moving easily through blood, causing painful blood clots and damage to tissues and organs throughout the body.

specimen (say: SPESS-uh-muhn) = a sample of body tissue used for testing or examination.

sperm (say: spurm) = cell found in semen that can unite with a female's egg after having sexual intercourse and lead to pregnancy.

spina bifida (say: SPYN-uh BIF-uh-duh) = a birth defect in which the spinal column does not close completely during the first month of pregnancy. There is usually nerve damage that can cause at least some leg paralysis (not being able to move) and other health problems. Girls who are sexually active should take folic acid because it can lower the risk of spina bifida, should a pregnancy occur.

spleen (say: SPLEAN) = an organ above the stomach and under the ribs on the left side of the body that helps fight infections, control the amount of blood in the body, and destroy old or damaged cells.

STD (say: S-T-D) = see sexually transmitted infection.

STI (say: S-T-I) = see sexually transmitted infection.

stillbirth (say: STILL-burth) = when a fetus dies during birth, or when a fetus dies late in a pregnancy when it was expected to live.

stroke (say: strohk) = when part of the brain doesn't get the blood it needs. This can happened because an artery is clogged by a blood clot or an artery tears and bleeds into the brain. Both types of stroke can cause brain cells to die. This may cause death or problems with movement, speech, understanding, and memory.

syphilis (say: SIF-uh-luhss) = a sexually transmitted infection (STI) caused by bacteria that progresses in stages. Without treatment, the infection can cause damage throughout the body and even death. Learn more about syphilis.

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tendon (say: TEN-duhn) = any of the bands of tough tissue that connect a muscle with a bone or other part.

testosterone (say: tuh-STOSS-tuh-rohn) = a male hormone that controls many of the changes males go through during puberty -- deeper voice, body and facial hair, and the making of sperm.

thrombocyte (say: THROM-boh-syt) = cells that play an important role in blood clotting. They are also called platelets.

thyroid (say: THEYE-roid) = a gland in the neck that makes hormones that control growth and metabolism.

toxic shock syndrome (say: TOK-sik shok SIN-drohm) = a rare but dangerous illness that affects the whole body. TSS is caused by bacteria that make toxins (poisons) in the body. Tampon use can make it easier for bacteria to enter the body. Symptoms include high fever that comes on suddenly, dizziness, rash, and feelings of confusion.

trans fat (say: tranz fat) = a type of fat, usually made by food manufacturers so that foods last longer on shelves or in cans. Eating transfats increases the risk of some illnesses, like heart disease.

transmit (say: TRANS-mit) = to give to someone else; to spread.

trichomoniasis (say: TRIK-uh-muh-NEYE-uh-suhss) = a common sexually transmitted infection (STI) caused by a parasite. Also called "trich." Learn more about Trichomoniasis.

TSS (say: T-S-S) = see toxic shock syndrome.

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urethra (say: yoo-REE-thruh) = a tube that carries urine from the bladder out of your body. In males, it also serves as a passage for the release of semen from the body.

urinary tract infection (say: YOOR-uh-nair-ee TRAKT ihn-FEK-shuhn) = an infection that happens in the bladder or tube leading to the bladder. It is usually caused by a type of bacteria.

urine test (say: YOOR-ihn test) = a strip of special paper is dipped into a sample of urine to look for problems, such as infection.

uterus (say: YOOT-uh-ruhss) = a pear-shaped, hollow organ in a female's pelvis where a baby develops during pregnancy. The uterus is made up of muscle with an inside lining called the endometrium (EN-doh-MEE-tree-uhm). The endometrium builds up and thickens during the menstrual cycle to prepare for a possible pregnancy each month. But if no pregnancy occurs, the extra tissue and blood are shed each month during a woman's period. Also called the womb.

UTI (say: U-T-I) = see urinary tract infection.

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vaccine (say: VACK-seen) = See immunization.

vagina (say: vuh-JEYE-nuh) = A muscular passage that leads down from the cervix to the outside of a female's body. During menstruation, menstrual blood flows from the uterus through the cervix and out of the body through the vagina. Also called the birth canal.

vein (say: vayn) = any of the thin-walled blood vessels that receive blood from capillaries and return it to the heart.

vigorous exercise (say: VIH-guh-ruhss EK-sur-syz) = physical activity that involves a high level of energy and effort. One who becomes winded or too out of breath to talk comfortably is doing vigorous activity. Running is vigorous exercise, while fast walking is moderate exercise, which requires less energy and effort.

virgin (say: VUR-juhn) = someone who has never had sexual intercourse.

virus (say: VEYE-russ) = a kind of germ that can infect cells and cause disease.

vitamin (say: VEYE-tuh-min) = a nutrient found in foods and that your body needs to work well. Not all foods contain the same vitamins, and some foods contain more of one vitamin than another. There are 13 vitamins that your body needs. If you do not get enough through the foods you eat, your doctor might suggest you take a vitamin supplement (pill).

vulva (say: VUHL-vuh) = the external female reproductive organ, which covers the entrance to the vagina. The vulva has five parts: mons pubis, labia, clitoris, urinary tract opening, and vaginal opening.

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white blood cell (say: wyt blud sel) = any of the blood cells involved in fighting infection and helping to heal wounds.

withdrawal (say: with-DRAW-uhl) = pulling the penis out of the vagina during sexual intercourse, before ejaculation.

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yeast infection (say: yeest ihn-FEK-shuhn) =  an infection in the vagina that happens when a fungus that is usually in the vagina grows too much.


Content last reviewed March 05, 2013
Page last updated June 05, 2014