Dictionary

idiocy, amaurotic familial See Tay-Sachs disease.

idiopathic Of unknown cause. For example, idiopathic pulmonary fibrosis is scarring of the lung tissue without a known cause.

idiopathic hypertrophic subaortic stenosis Narrowing of the left ventricle of the heart just below the aortic valve through which blood must pass on its way up into the aorta. The narrowing cuts the flow of blood and is due to hypertrophic cardiomyopathy (HCM), a genetic disorder of the heart. HCM is the leading cause of…

idiopathic sclerosing cholangitis See primary sclerosing cholangitis.

idiopathic torsion dystonia See dystonia, idiopathic torsion.

IgA Immunoglobulin A, an antibody.

IgA nephropathy A chronic disorder caused by the accumulation of immunoglobulin A deposits within the filtering units of the kidney, resulting in the presence of blood and protein in the urine and swelling in the extremities. The disease progresses with time and may ultimately lead to renal failure. High blood pressure is one complication of…

IgD Immunoglobulin D, an antibody.

IgE Immunoglobulin E, an antibody.

IgG Immunoglobulin G, an antibody.

IgM Immunoglobulin M, an antibody.

IHSS Idiopathic hypertrophic subaortic stenosis.