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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All terms that start with the letter I
  • iatrogenic

    Resulting from medical treatment.

  • ichthyosis

    An inherited skin disorder that produces dry, rough, scaly skin.

  • identical twins

    Twins formed from a single egg. They are of the same gender and have the same genetic makeup. Also called…

  • idiopathic

    Without a known cause.

  • ileitis

    Inflammation of the lower part of the small intestine.

  • ileum

    The lower part of the small intestine.

  • ileus

    Lack of movement of digested food and juices through the gastrointestinal tract. May be due to a blockage of the…

  • ilium

    The flared portion of the pelvis. The hip bone.

  • IM


  • immune

    Resistant to a particular disease.

  • immunity

    Resistance of the body to infection.

  • immunization

    The process of making an individual immune by vaccination or inoculation.

  • immunoglobulin

    A serum protein involved in immunity. An antibody.

  • impetigo

    Skin infection characterized by erupting sores. Caused by staphylococcus or streptococcus bacteria.

  • impotence

    Inability of a male to achieve erection and orgasm.

  • in situ

    In its original place. Carcinoma in situ means cancer that hasn’t spread to other locations.

  • incision

    A cut.

  • incisor

    Any of the front four teeth on either the upper or lower jaw.

  • incompetent

    1. Unable to make rational decisions. 2. Not functioning properly.

  • incontinence

    Inability to hold urine or feces.

  • incubate

    To provide the proper conditions for growth.