A homocysteine test measures the amount of homocysteine in your blood. Homocysteine is a type of amino acid, a chemical your body uses to make proteins. Normally, vitamin B12, vitamin B6, and folic acid break down homocysteine and change it into other substances your body needs. There should be very little homocysteine left in the bloodstream. If you have high levels of homocysteine in your blood, it may be a sign of a vitamin deficiency, heart disease, or a rare inherited disorder.
Other names: total homocysteine, plasma total homocysteine
A homocysteine test may be used to:
You may need this test if you have symptoms of a vitamin B or folic acid deficiency. These include:
You may also need this test if you are at high risk for heart disease because of prior heart problems or a family history of heart disease. Excess levels of homocysteine can build up in the arteries, which may increase your risk of blood clots, heart attack, and stroke.
A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
You may need to fast (not eat or drink) for 8–12 hours before a homocysteine test.
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
If your results show high homocysteine levels, it may mean:
If your homocysteine levels were not normal, it doesn’t necessarily mean you have a medical condition needing treatment. Other factors can affect your results, including:
If you have questions about your results, talk to your health care provider.
If your health care provider thinks a vitamin deficiency is the reason for your high homocysteine levels, he or she may recommend dietary changes to address the problem. Eating a balanced diet should ensure you get the right amount of vitamins.
If your health care provider thinks your homocysteine levels put you at risk for heart disease, he or she will monitor your condition and may order more tests.