Drinking water is usually allowed during the fasting period before a blood test, as plain water does not interfere with most test results. However, it is best to follow the instructions given by the doctor who ordered the test or the lab where it will be performed.
In general, fasting before a blood test means avoiding all food and beverages, except for plain water. When fasting is required, it's important to pay attention to the recommended duration, which may vary depending on the type of test being done.
Before undergoing any lab test, it's important to clarify any questions with the ordering physician or the clinic or lab performing the test. Following the instructions properly helps ensure accurate and reliable results. Learn more about how to interpret blood test results.