How do cancer blood tests work?In combination with other tests, blood work can give your provider important information about:Chemicals and proteins in your blood that might indicate cancer.Blood cell levels that are too high or too low, perhaps because of cancer.Stage of cancer.Effectiveness of treatment(s).Whether cancer has come back (recurrence).How do I prepare for a cancer blood test?Your healthcare provider will give you specific instructions on how to prepare for your blood test. These guidelines may differ depending on the type of test you need.In some cases, you might have to fast for eight to 12 hours prior to the test. That means you shouldn’t eat or drink anything besides water. You also may need to avoid certain medications beforehand.What should I expect during cancer blood work?Collecting a sample of your blood should only take a few minutes. Your healthcare provider will:Wrap a tight band (tourniquet) around your upper arm.Clean an area of your skin, usually on the ins...
