A person should only fast before a blood test if their doctor or healthcare professional specifically instructs them to do so. Not all blood tests require fasting. If a doctor or healthcare ...

Blood draws for several kinds of diagnostic tests require you to fast for several hours. Eating or drinking anything besides water can skew the results, leading to you needing to be retested. You may ...

Some common blood tests require you to fast beforehand to help make sure the test results are as accurate as possible. You can typically still drink water during this period, but is drinking tea ...