HAART

Highly Active Antiretroviral Therapy, a term used to describe anti-HIV combination therapy with three or more drugs.

haematocrit

(hee-ma-toe-krit)

Measurement of the proportion of red cells in the blood.

haematology

(hee-ma-tol-o-gee)

Study of blood conditions. Also used to describe a range of biochemical tests carried out on the blood.

haemoglobin

(hee-ma-glow-bin)

Red-coloured, oxygen-carrying chemical in red blood cells.

haemophilia

(hee-ma-fill-ee-uh)

Inherited illness in which the blood does not always clot, often requiring injections of blood clotting agents.

half-life

The amount of time it takes for half a dose of any drug to be eliminated from the body.

helper cell

An alternative name for CD4 T cells.

hepatic

(he-pa-tick)

To do with the liver.

hepatitis

(he-pa-ty-tuss)

Inflammation or infection of the liver.

hepatotoxicity

(he-pa-toe-tox-i-cit-tee)

Side-effects affecting the liver.

herpes simplex

(her-peez sim-plex)

A viral infection which may cause sores around the mouth or genitals.

herpes viruses

Family of viruses which can cause disease in HIV infection, e.g. cytomegalovirus and herpes zoster.

hickman catheter

A type of catheter that is surgically implanted, with one end leading into a large vein in the chest, and the other end remaining outside the chest.

HICKMAN is a registered trade mark of C R Bard Inc

histology

(hiss-tol-o-gee)

Examining a sample of cells under a microscope to determine if they are normal or if there is evidence of infections or tumours.

historical control

A comparison group of people not taking an experimental drug, taken from previous clinical trials.

HIV

Human immunodeficiency virus, the virus which causes AIDS. There are two variants: HIV-1, and HIV-2. HIV-1 is by far the most common world-wide. See subtype for more information.

homeopathy

(ho-mee-o-pu-thee)

A therapy which aims to treat illness using tiny quantities of the substance that caused the illness, or of a substance that causes similar symptoms.

hormone

A chemical which stimulates or suppresses cell and tissue activity.

human papilloma virus (HPV)

(hu-man pa-pill-low-muh vy-russ)

A group of wart-causing viruses which are also responsible for cancer of the cervix and some anal cancers.

hyper

(hy-puh)

Prefix meaning higher than usual.

hyperglycaemia

(high-puh-gly-see-me-uh)

Raised concentration of sugar in the blood.

hyperlipidaemia

(high-puh-li-pi-dee-mee-uh)

High levels of fat in the blood.

hypersensitivity

(high-puh-sen-sit-i-vit-ee)

An allergic reaction.

hypertension

(high-puh-ten-shun)

Raised blood pressure.

hypertriglyceridaemia

(high-puh-try-gli-si-ry-dee-me-uh)

High levels of triglycerides in the blood.

hypo

(high-po)

Prefix meaning lower than usual.

hypoxaemia

(high-pox-ee-mee-uh)

Reduced amounts of oxygen in the blood, usually caused by pneumonia.