how long should you fast for blood work

For blood work that requires fasting, the typical fasting duration is between 8 to 12 hours before the test. During this time, only water is allowed—no food, drinks other than water, smoking, gum chewing, or exercise. The exact fasting duration can vary depending on the specific blood test being performed, so it is important to follow the instructions given by the healthcare provider. Common blood tests that require fasting include glucose (blood sugar) tests, triglycerides (part of the cholesterol panel), and some iron tests. Scheduling the blood test in the morning is often recommended so that most of the fasting period occurs overnight while sleeping. After the blood is drawn, eating can resume immediately. People with certain conditions, such as diabetes, should consult their doctor regarding fasting and medication management to avoid complications like low blood sugar during the fast.