Dictionary

Body systems

Anatomy and the conditions of each body system, from the heart and lungs to the skin.

hyperparathyroidismOveractivity of the parathyroid glands, which make too much parathyroid hormone.

hyperphosphatemiaA blood phosphate (phosphorus) level above normal.

hyperpigmentationPatches of skin that are darker than the skin around them.

hyperplasiaAn increase in the number of cells in a tissue or organ, making it larger.

hypersensitivityAn overreaction of the immune system to a substance that is usually harmless.

hypertensionBlood pressure that stays higher than normal, at or above 130/80 mm Hg by current US guidelines.

hypertensive crisisA severe rise in blood pressure, generally to a systolic above 180 or a diastolic above 120 mm Hg.

hyperthermiaA body temperature that is higher than normal because the body takes in or makes more heat than it can lose.

hyperthyroidismA condition in which the thyroid gland makes too much thyroid hormone.

hypertrophyAn increase in the size of an organ or tissue because its cells grow larger.

hyperventilationBreathing faster or deeper than the body needs, so too much carbon dioxide is breathed out.

hypervolemiaA higher than normal volume of fluid in the blood vessels; also called fluid volume excess or fluid overload.

hypocalcemiaA blood calcium level below normal.

hypochloremiaA blood chloride level below normal, under 98 mEq/L.

hypoglycemiaA blood glucose level below normal, under 70 mg/dL.

hypokalemiaA blood potassium level below normal, under 3.5 mEq/L.

hypomagnesemiaA blood magnesium level below normal.

hyponatremiaA blood sodium level below normal, under 135 mEq/L.

hypoparathyroidismA condition in which the parathyroid glands make too little parathyroid hormone.

hypophosphatemiaA blood phosphate (phosphorus) level below normal.

hypospadiasA birth defect in which the opening of the urethra is on the underside of the penis instead of at the tip.

hypotensionBlood pressure lower than normal, generally below 90/60 mm Hg in an adult.

hypothalamusA small area at the base of the brain that controls body temperature, hunger, thirst, sleep and many hormones.

hypothyroidismA condition in which the thyroid gland makes too little thyroid hormone.

hypoventilationBreathing that is too slow or too shallow to remove enough carbon dioxide from the body.

hypovolemiaA lower than normal volume of fluid in the blood vessels; also called fluid volume deficit.

hypovolemicHaving too little blood or fluid in the blood vessels.

hypovolemic shockShock from a large loss of blood or body fluid, so there is too little volume in the blood vessels to supply the organs.

hypoxiaA lower than normal level of oxygen in the body's tissues.

hysterectomySurgery to remove the uterus.

ideationThe forming of thoughts or ideas, especially repeated thoughts about a particular act.

idiopathicHaving no known cause.

IgAImmunoglobulin A: a kind of antibody found mostly in the body's linings and in saliva, tears and breast milk.

IgDImmunoglobulin D: an antibody found mostly on the surface of B cells, where it helps start an immune response.

IgEImmunoglobulin E: the type of antibody involved in allergic reactions and in fighting parasites.

ileumThe last and longest part of the small intestine, which joins the large intestine.

ileusA slowing or stopping of the normal movement of the intestines, with nothing physically blocking them.

iliacHaving to do with the ilium, the large, wing-shaped upper part of the hip bone.

iliumThe large, wing-shaped upper part of each hip bone.

imbalanceA lack of balance: too much or too little of something the body needs to keep at a steady level.

immobilityBeing unable to move about freely, such as being kept in bed or a chair.

immuneProtected against a disease, or having to do with the body's defense system against germs and other foreign things.

immune responseThe way the body recognizes and defends itself against germs and other substances it sees as foreign.

immune systemThe body's defense system of cells, tissues and organs that fights germs and other foreign substances.

immunityThe body's ability to resist or fight off a particular infection or disease.

immunocompromisedHaving an immune system that is weaker than normal at fighting infection.

immunodeficiencyA state in which the immune system is weaker than normal and cannot fight infection well.

immunoglobulinAn antibody: a protein made by B cells that recognizes and helps destroy a specific germ or foreign substance.

immunologyThe branch of science and medicine that studies the immune system.

immunotherapyTreatment that uses or changes the body's immune system to fight disease.