homocysteine (HCY) test, a blood test used to detect levels of homocysteine, which, if increased, may act as an independent risk factor for ischemic heart disease, cerebrovascular disease, peripheral arterial disease, and venous thrombosis. This test should be considered for screening in individuals with progressive and unexplained atherosclerosis despite normal lipoproteins and in the absence of other risk factors and in those with an unusual family history of atherosclerosis.
