Homocysteine Serum / Plasma
Homocysteine is an amino acid. It is converted into cysteine with the help of B vitamins. Cysteine maintains structural and functional integrity of proteins. It also helps in copper, iron and zinc metabolism. High levels of homocysteine are associated with atherosclerosis and blood clots. The test is performed to measure the levels of homocysteine in the bloodstream.
Why the test is ordered?
A homocysteine blood test may be ordered to detect a rare inherited disease (homocystinuria) and also to detect folic acid or vitamin B12 deficiency. The test may also be helpful in determining the cause for blood clots.
When is the test ordered?
The test may be ordered if a physician suspects vitamin B12 or folate deficiency in an individual owing to these signs and symptoms: weakness, loss of appetite, shortness of breath, numbness in the hands, arms and legs and rapid heart rate. The test may be recommended to evaluate an individual's risk of developing heart disease considering other risk factors and age. The test may also be ordered if a new-born or child is suspected of having homocystinuria based on increased levels of methionine.
How is the sample collected?
A blood sample from the arm is collected.
How to prepare for the test?
Individuals taking the test are advised not to eat and drink for up to ten to twelve hours before the test.
