For most fasting blood tests, it is recommended to fast for 8 to 12 hours before the test. During this fasting period, you should not eat or drink anything except plain water. Some blood tests may require avoiding alcohol for 24 hours before the test as well. Fasting helps ensure that the test results are accurate by eliminating the influence of food and drink on blood levels of glucose, triglycerides, and other substances tested. It is also advised to avoid smoking, chewing gum, and strenuous exercise during the fasting period. Drinking water is allowed and even recommended to keep veins hydrated for easier blood draw. The exact fasting time can vary depending on the specific blood test, so it is important to follow the instructions given by the healthcare provider. Scheduling the blood test for early in the morning can make fasting easier since most of the fasting time will be while sleeping. Summary:

• Typical fasting duration: 8 to 12 hours
• Allowed during fasting: plain water
• Avoid: food, alcohol (usually 24 hours before), gum, smoking, exercise
• Follow healthcare provider's specific instructions
• Schedule test in morning for convenience