A congenital disorder in which the rectum and sometimes the lower part of the colon lack the cells that control the contractions of the intestines.

A disease in which there is an excess of a type of immune cell called histocytes, leading to varied symptoms that may affect any part of the body.

The abbreviation for human immunodeficiency virus, which is the cause of AIDS.

human leucocyte antigen

Human leukocyte antigen B27, a protein present on the surface of white blood cells in some autoimmune diseases and sometimes in healthy individuals

A laboratory test that is used to help strengthen or confirm a diagnosis of the spondoarthritides. It is not a definitive test but is used as one piece of evidence tohelp build up an overall picture.

A type of amino acid (the building block of all proteins).

an intestinal parasite.

A substance produced by a gland in one part of the body and carried by the blood to the organs or tissues where it has an effect.

The administration of female hormones in cases where they are not sufficiently produced by the body. Abbreviated to HRT.

Unresponsive to hormone therapy.

A group of physical signs affecting one side of the face that indicate nerve damage.

An animal or plant that supports a parasite.

A thick form of mucus that prevents the sperm from entering the cervix.

An abbreviation for human papilloma virus, a sexually transmitted virus that can cause genital warts and may also have a role in the development of various cancers.

Abbreviation for hormone replacement therapy, the administration of female hormones in cases where they are not sufficiently produced by the body.

Herpes simplex virus

Also known as antiphospholipid syndrome. A type of autoimmune disease, caused by overactivity of the immune system. It is associated with thrombosis and, in women of childbearing age, recurrent miscarriage.

A blood test that detects antigens (a substance that can trigger an immune response) on white blood cells.

A sexually transmitted virus that can cause genital warts and may also have a role in the development of various cancers.

A tan patch on the skin that grows slowly, and becomes mottled, dark, thick and nodular. It occurs chiefly during middle and old age.

high vaginal swab

A complication of pregnancy in which an abnormal fertilised egg implants in the uterus and grows multiple cysts - looking like a bunch of grapes - instead of a normal embryo. Occasionally it can develop into a rare type of cancer called choriocarcinoma.