You typically need to fast for 8 to 12 hours before blood work, depending on the specific test your doctor orders. During fasting, you should not eat or drink anything except plain water. Drinking water is encouraged to stay hydrated for easier blood draw. Avoid chewing gum, smoking, exercising, and certain medications unless your doctor advises otherwise. Some tests may require longer fasting or no fasting at all, so it is important to follow your healthcare provider's specific instructions. Fasting helps ensure accurate blood test results by preventing food and drink from affecting blood sugar, triglycerides, and other measured substances. It is common to schedule blood tests in the morning so most of the fasting occurs while sleeping. In summary:
- Fast 8-12 hours before blood work (varies by test)
- Only drink plain water during the fast
- Avoid gum, smoking, and exercise
- Follow your doctor's specific instructions
This fasting protocol applies mainly to tests like blood glucose, lipid panels (cholesterol and triglycerides), and some iron tests. Other blood tests may not require fasting at all.
