Health Class
Social Science Class
Science Class
Glossary

Find a word that starts with:
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

AIDS
"AIDS" stands for Acquired Immune Deficiency Syndrome. AIDS is the name given to a group of diseases and conditions that happen when the body's immune system is damaged by HIV. We say someone who is HIV-positive has AIDS when they start getting very sick from the virus. People with AIDS can have infections in the lungs, brain and eyes. They can lose a lot of weight, get diarrhea and get cancer.
top

AIDS Dementia Complex
This is an illness that affects the brain in people who have HIV or AIDS. People with it can have trouble with coordination, have mood swings, have a bad memory and have trouble thinking in general. This is a very common problem in people with HIV/AIDS and it gets worse as time passes once you have it.
top

AIDS-Related Complication
This is what we call any kind of sickness that you get because your immune system is weak from HIV/AIDS. It's either when an Opportunistic Infection becomes active and starts to make you sick. Or it's a disease or problem that isn't an infection - meaning it doesn't come from germs.
top

Antibodies
These are made by the immune system to fight infection. They are very small particles in the blood or other body fluids that work against bacteria, viruses and other harmful things in the body. If they are working right and the harmful "invader" is not too serious, they can sometimes find, kill or make it harmless. The body's antibodies cannot kill HIV.
top

Antigen
Anything that makes the immune system produce antibodies. Antigens are usually "foreign" things such as bacteria or viruses that invade the body.
top

Bacteria
A microscopic organism or germ (it can't be seen by the human eye unless it's under a microscope) made up of a single cell. Many bacteria can cause disease in humans.
top

CD4 Cell
A type of cell that protects the body against infections caused by viruses, fungi (such as yeast) or protozoa. CD4 cells send a message to the rest of the body to make antibodies to fight infections.
top

CD4 Count
This is a blood test that measures the number of CD4 cells in your body. It's the test that gives the best idea of what stage of HIV disease you are at and strong your immune system is. It should be done every four to six months, or more often if your viral load seems to be rising or if you've been sick.

  • In HIV-negative adult men, the usual CD4 count ranges from 400 to 1,200 CD4 cells per cubic millimetre of blood.
  • In HIV-negative adult women, it ranges from 500 to 1,600 CD4 cells per cubic millilitre.
  • It is important to note that test can vary from lab to lab but that these CD4 counts are usual for HIV-negative adults.

top

Chlamydia
A bacteria that causes one of the most common sexually transmitted diseases (STDs). It can infect the throat, rectum, penis, vagina, and eyes. Many people, especially women, don't have any symptoms and don't even know it if they have it. Chlamydia can be treated with antibiotics.
top

Cocktail, The
See Combination Therapy.
top

Co-infection
If you have a certain type of infection in addition to HIV or AIDS, it's called a co-infection. This type of infection is something anyone could get, whether or not they have HIV or AIDS. Examples include hepatitis and tuberculosis.
top

Combination Therapy
Three or more drugs or treatments used together to get the best results against HIV infection and/or AIDS.
top

Cytomegalovirus (CMV)
A herpes virus. About half of the adults in Canada have been infected with CMV. If you have a healthy immune system, you might not know you have it. Maybe you'll get a short sickness that's like the flu or you may have no symptoms at all. If your immune system is weak, perhaps from HIV/AIDS, it can cause problems in your eyes, digestive system, lungs or brain.
top

DNA (Deoxyribonucleic Acid)
A very small particle in our body, inside our genes. DNA carries the genetic information that allows cells to reproduce (make new cells). DNA makes up the main part of chromosomes, which are the structures that pass on hereditary (from your parents) information.
top

Enzyme
A protein that speeds up a chemical reaction.
top

Fungus
The name of a group of organisms that grow on or life off of other things. You can find them in nature and inside the body. Both yeast and moulds are fungi.
top

Germ
A name given to certain tiny bacterias or organisms that cause diseases.
top

HAART
Highly Active Antiretroviral Therapy, a term for a very powerful, effective anti-HIV treatment. The usual HAART treatment combines three or more different drugs. These treatments have been shown to lower the amount of virus so that it becomes hardly noticeable in a person's blood, but that doesn't the person is cured.
top

HIV
"HIV" stands for Human Immunodeficiency Virus.

  • Human means it affects humans only
  • Immunodeficiency means that something is deficient, or there is not enough of it, in the immune system
  • Virus is something that infects someone, and that can be spread from one person to another
  • HIV is the virus that causes AIDS.

top

Human Papilloma Virus (HPV)
A virus that causes genital warts. The warts appear around the head of the penis, the vulval lips, in the vagina, on the cervix, on the anus or in the rectum. HPV can lead to cervical dysplasia (a condition that might lead to cancer) and cervical cancer in women and anal dysplasia and anal cancer in men.
top

Immune System
The body's natural defence system that fights infections and disease.
top

Kaposi's Sarcoma (KS)
Cancerous lesions on the skin and/or organs caused by blood vessels growing wrong. It usually looks like pink or purple painless spots on the surface of the skin or in the mouth. It can also appear in the intestines, lymph nodes and lungs, and can also attack the eyes.
top

Lesion
Any change in body tissue caused by disease. For example, an infected area or sore in a skin disease.
top

Lymph or Lymph Fluid
A yellowish fluid that carries lymphocytes. Lymph is made from tissue fluids and is collected from all parts of the body. It goes into the blood through lymphatic vessels.
top

Lymph Nodes
Special areas in the body where white blood cells and other important immune
cells are found. Also called glands.
top

Lymphatic System
The tissues and organs that create, store and carry white blood cells, which fight infection and other diseases. This system includes lymphoid organs, lymph nodes and lymphatic vessels.
top

Lymphatic Vessels
A network of channels in the body, like blood vessels, that carry lymph to the immune system and into the blood.
top

Lymphocyte
A type of white blood cell.
top

Lymphoid Organs
Organs act as a filter for the body. They trap invaders (such as bacteria and viruses) and hands them over to immune cells that are grouped together there. They include tonsils, adenoids, lymph nodes, spleen, thymus and other tissues.
top

Lymphoid Tissue
Tissue involved in the making of lymph fluid, lymphocytes and antibodies.
top

Opportunistic Infections
Particular infections that cause disease in someone with a damaged immune system. These illnesses don't usually cause disease in someone with a healthy immune system. People with HIV infection can have opportunistic infections of the lungs, brain, eyes and other organs.

Opportunistic infections common in people with AIDS include Pneumocystis carinii pneumonia (PCP), Kaposi's sarcoma, other parasitic, viral and fungal infections and some types of cancers.
top

Oral candidiasis
The most common fungal infection in people who have HIV. Candida is a yeast found in most people and is normally kept under control by your immune system and "friendly" bacteria in your body. In the mouth, oral candidiasis looks like white patches on your gums and your tongue and is also known as thrush.
Top

Oral hairy leukoplakia
A viral infection that gives you a hairy white coating on the inside of your mouth and on the sides of your tongue. Experts think it might be caused by the Epstein-Barr virus and with the human papilloma virus (HPV).
top

Parasite
A plant or animal that lives and feeds on or within another living thing. It usually causes harm to that living thing.
top

Parotid gland
A gland located near the ear that makes saliva.
top

Prophylaxis
A treatment that helps to prevent a disease or condition before it happens or comes back.
top

Protease
An enzyme that HIV uses to break up large proteins into smaller ones. The smaller proteins then make copies of HIV or new viruses.
top

Protease Inhibitors (PIs)
A drug that blocks the action of the HIV protease enzyme. By blocking that enzyme, it prevents HIV from replicating, even in cells that are already infected. Some examples of these drugs are saquinavir, nelfinavir and indinavir.
top

Proteins
Organic compounds found naturally in all living cells. Some hormones and all enzymes are proteins.
top

Protozoa, Protozoan
A single-cell living thing that can only reproduce itself when it's living inside another living thing.
top

Replication, Replicating
What we call it when viruses reproduce, or make new versions of themselves.
top

Retrovirus
A type of virus. While regular viruses store their genetic information on a DNA molecule, retroviruses store it on a RNA molecule. HIV is an example of a retrovirus.
top

Reverse Transcriptase Inhibitors (RTIs)
A drug that blocks retroviral replication (stops it from making new versions of itself). So it doesn't kill or harm a virus, just slows down its spread through the body. RTI drugs include AZT, ddI, 3TC, d4T, abacavir, nevirapine and efavirenz.
top

RNA (Ribonucleic Acid)
This is similar to DNA. It's a place where certain kinds of cells carry their genetic information. HIV carries its genetic information in RNA, while most viruses store it in DNA.
top

Seroconversion
When the body develops antibodies to an antigen. When a person develops antibodies to HIV, we say they seroconvert from antibody-negative to antibody-positive. It can take a few weeks to several months for antibodies to the virus to develop. After antibodies to HIV appear in the blood, a person would test positive on an HIV test.
top

Side Effects
An effect of a drug or therapy that isn't wanted. It usually means a negative effect, such as headache, skin rash or liver damage.
top

T Cells
See CD4 Cells.
top

T4 Cells
See CD4 Cells.
top

Thrush
See oral candidiasis.
top

Toxoplasmosis, Toxo
A sickness caused by a protozoan called Toxoplasma gondii. You can get toxo by eating raw or undercooked meat that's contaminated with the germ. It may also be found in the feces of cats. Toxo gets into your body through your mouth and digestive system. If your immune system is weakened, toxo can make you really sick.
top

Vaccine
A medicine that contains a small amount of a particular antigen. It's designed so you won't get sick, but the immune system system will respond and learn how to fight the antigen. Later, if you come in contact with that germ or bacteria, you won't get sick. We have vaccines for some illnesses, such as Hepatitis A and B, but not HIV.
top

Viral Load
The measurement of the amount of HIV virus in the blood. A viral load test shows you many copies of itself HIV has made in your body. Doctors watch HIV-positive people's viral load because it shows how much disease is progressing. It's better to have a low viral load.
top

Virus
A germ that reproduces within the cells of the person it infects. In people, viruses cause diseases such as measles, mumps, polio, influenza and the common cold. Viruses can be spread from one person to another.
top

Wasting Syndrome
A complication of HIV or AIDS disease. It's when a person loses at least 10 per cent of their body weight without try to lose this weight. Usually, the person also has ongoing diarrhea, weakness and fever.
top

Other HIV/AIDS glossaries on the Internet:

Glossary of HIV/AIDS-Related Terms

HIV / AIDS Treatment Thesaurus

Medical Terms 101

National AIDS Manual

 
 
 
 
Hospital for Sick Children University of Toronto Positive Youth Outreach CATIE