| B
| C
| D
| E
| F
| G
| H
| I
| J
| K
| L
| M
| N
| O
| P
| R
| S
| T
| U
| V
| W



A localized collection of pus surrounded by inflamed tissue.


A disorder of the skin caused by inflammation of the skin glands and hair follicles; specifically, a form found mainly in adolescents and marked by pimples especially on the face.

Active-controlled trial

A research study that compares the test drug or treatment to standard-of-care therapy (vs placebo).

Adverse reaction

An unwanted effect resulting from taking a drug treatment. Effects may occur suddenly or develop over time (ex: headache, nausea, rash, etc.).

Advocacy and support groups

Organizations and groups that actively support patients and their families by providing valuable resources, including self-empowerment and coping tools.


AIDS (acquired immunodeficiency syndrome) is the most advanced stage of infection with human immunodeficiency virus (HIV). HIV/AIDS can be spread through unprotected sex with an infected person or by sharing drug needles or through contact with the blood of an infected person.


A substance, such as pollen, that causes an allergy.


Medications which may be used for the treatment of dyskinesias (involuntary movement) and wearing off.

Anaplastic lymphoma kinase (ALK) gene

This gene sends signals that make cells grow and divide.


A surgical connection made between two structures (usually tubular ones) such as blood vessels or loops of the bowel. Ends of these two structures are usually stitched or stapled together (anastomosed) by a surgeon after a part of the bowel has been removed.


Low red blood cell count (low hemoglobin). The dilute blood is less able to carry oxygen. Symptoms may include tiredness, pale appearance, palpitations (irregular heart beat) and shortness of breath. Iron deficiency anemia is common. In adults, it is often due to blood loss and sometimes to poor absorption or intake of iron. Blood loss in adults most commonly occurs from the gastrointestinal tract.

Ankylosing spondylitis

A type of arthritis of the spine; it causes inflammation between the vertebrae (bones that make up your spine) and in the joints between your spine and pelvis. In some people, ankylosing spondylitis can affect other joints.


Chemical substances that stop the growth of or kill bacteria, parasites and fungus. Antibiotics do not treat viral infections – antiviral drugs may treat some viruses.


Medications that block neurotransmitter systems.

Anti-citrullinated protein (CCP) antibody

Autoantibodies (antibodies directed against one or more of an individual’s own proteins) that are frequently detected in the blood of rheumatoid arthritis patients.


Any substance that can stimulate the immune system to produce antibodies that combine specifically with them.

Apocrine gland

Apocrine glands are special sweat glands found in hairy areas of the body such as the armpits and groin.


A surgical operation to remove the appendix.


Swelling (inflammation) of the appendix.


A tube-shaped sac located at the junction of the small and large bowel in the lower right abdomen. The function of the appendix is unknown.


A treatment group in a randomized trial. Most randomized trials have two "arms", but some have three "arms" or more.



The practice of using essential oils (generally plant-based) to improve health or a person’s mood.


A condition that causes pain and inflammation within a joint. For more information click here

Art therapy

Helps people manage physical and emotional problems by expressing themselves through art.


This is a rare childhood disease that affects the brain as well as other parts of the body.


Ophthalmic atropine may be used before eye examinations to dilate (open) the pupil (the black part of the eye). This medication can also be used to relieve pain caused by swelling and inflammation of the eye.

Autoimmune disease

An illness that occurs when the body tissues are attacked by its own immune system. The immune system is designed to “seek and destroy” disease in the body, including infectious agents. Patients with autoimmune diseases frequently have unusual antibodies circulating in their blood that target their own body tissues.


An immune response against an organism’s own cells and tissues: antibodies or T cells that attack molecules, cells, or tissues of the organism producing them. Any disease that results from such an aberrant immune response is termed an autoimmune disease.


Azathioprine is used with other medications to prevent transplant rejection (when the transplant is attacked by the body’s immune system) in people who received kidney transplants. It can also be used to treat severe rheumatoid arthritis (a condition in which the body’s immune system attacks the joints, causing pain, swelling, and loss of function) when other therapies have not helped.