Dictionary of Medical Terms

Gain a better understanding of medical terminology by searching our dictionary of more than 1,300 terms.

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  • ulcerative colitis

    A chronic inflammatory disease of the large intestine characterized by bloody diarrhea.

  • ulcer

    A localized sore in the skin or mucosal surfaces.

  • typhus

    An infectious disease spread to people by the bite of ticks, mites, fleas and lice. Typhus is characterized by high…

  • typhoid fever

    A bacterial infection with Salmonella typhi transmitted by contaminated water, milk or other foods. Proper sanitation and hygiene prevent the…

  • tympanic membrane

    The eardrum.

  • tussis


  • tumor

    Overgrowth of tissue.

  • tuberculosis

    An infectious disease caused by bacteria and characterized by the formation of tubercles in various tissues of the body, especially…

  • tuberculin

    A protein injected into the skin to test for tuberculosis infection.

  • TSH

    Thyroid-stimulating hormone. A pituitary hormone that stimulates thyroid hormone production.

  • truss

    A device to keep a hernia in its proper place.

  • trisomy

    The presence of an extra chromosome in addition to the usual pair. Down syndrome is an example of a condition…

  • tricuspid valve

    The heart valve between the right atrium and the right ventricle.

  • trichomoniasis

    Infection with Trichomonas protozoa. Frequently causes vaginal itching and discharge in women. It’s usually acquired by sexual contact with an…

  • trichinosis

    Infection with a roundworm caused by consumption of larvae in undercooked pork or other infected meat.

  • triceps

    A muscle of the arm used to extend the forearm.

  • triage

    A system of assigning priorities of medical treatment based on urgency, severity of injury and chance for survival.

  • trench mouth

    An acute, severe bacterial infection of the gums and lining of the mouth.

  • trauma

    Injury produced by an external force.

  • transplantation

    The transfer of living organs or tissue from a donor to another person or from one area in the body…

  • transfusion

    Introduction of blood or blood products through a vein into the body’s circulation.