can i drink coffee before a blood test fast
Patient Information: Fasting Blood Tests. If your doctor orders a fasting blood test, you should not have anything to eat or drink for 12 hours before you go to the laboratory to have your blood taken.Some examples of fasting blood tests are fasting glucose, fasting triglycerides, fasting lipids and glucose tolerance.atient Information: Fasting Blood Tests. If your doctor orders a fasting blood test, you should not have anything to eat or drink for 12 hours before you go to the laboratory to have your blood taken.