can you drink water before a fasting blood test
Fasting blood glucose test. Do not eat or drink anything except water for 8 to 10 hours before a fasting blood glucose test. These are used to diagnose diabetes, a condition caused by too much glucose (sugar) in the blood.n other cases, you will be instructed not to eat or drink (other than water) before your test. This is known as a fasting blood test. You may also be told not to drink alcohol or not to smoke before your test.