A homocysteine test measures the amount of the amino acid homocysteine in the blood. You may have high levels of homocysteine when cholesterol, white blood cells, calcium, and other substances (plaque) build up in your blood vessels. This buildup may increase your chances of having a heart attack, stroke andblood clots in the lungs (pulmonary embolism) or deep veins of the legs (deep venous thrombosis).
Homocysteine testing may be most useful in checking the overall risk of heart disease for people who have a strong personal or family history of heart disease but who do not have other risk factors that can be controlled, such as smoking or high blood pressure. Homocysteine testing also may be useful for people who have early heart disease but who do not have known risk factors and for people who have had unexplained deep vein thrombosis or stroke.
