How To Fast Before a Blood Test

How To Fast Before a Blood Test

Fasting before a blood test is important to obtain accurate readings. When you consume food your body has to process the food's components as they travel through your bloodstream. Blood tests examine a variety of blood and sugar levels that can be compromised if foreign entities such as food contaminate blood painting an inaccurate picture. Fasting beforehand allows the physician to obtain a clear picture of your bodily functions for an accurate diagnosis. Blood tests are a common way for your doctor to monitor your health and nutritional status check for the presence of health conditions and assess your risk for disease. While the level of most blood components will not change rapidly from consuming nutrients some of the substances in your blood will be affected by eating or drinking in the hours prior to the test. Before having blood tests completed be sure to check with your doctor so you know if you can eat or need to fast prior to the test. Because blood glucose and blood fats can be elevated for several hours after eating fasting glucose triglyceride or cholesterol are the most common tests that require fasting. Certain hormone measurements such as testosterone and cortical may require an early morning blood sample but will not require fasting. Your doctor may even ask you to avoid alcohol certain nutritional supplements or medications prior to a test but as a rule you can take medications and supplements according to your usual schedule even when fasting. Fasting before a blood test is typically required for fasting glucose fasting lipid panel fasting metabolic panel fasting cholesterol HDL or triglyceride tests. These tests look for cholesterol and glucose levels in your blood and any food consumed before the test will provide an inaccurate reading. Your doctor may recommend a certain time period for fasting the standard amount of time is about eight to 15 hours of no food before having blood drawn. Schedule your blood test for early in the morning so you'll only need to fast overnight to meet requirements. Fast for eight hours before a glucose test. The test is typically conducted in the morning while your body is still in a resting place for a more accurate reading. You must fast at least 15 hours before taking a cholesterol blood test to get an accurate reading on triglycerides. The American Heart Association warns against quick cholesterol tests you find in malls and health fairs because fasting is imperative to obtaining an accurate result. Stay hydrated and drinks plenty of water. Take any medication that your doctor prescribed to you except for corticosteroids estrogen or androgens oral contraceptives some diuretics anti psychotic medications including haloperidol some antibiotics and niacin. Do not smoke drink any other liquid than water or exercise during your fast. Even chewing gum is off limits. Any of these elements can adversely affect your test results.

 Because some tests are ordered at the same time some requiring fasting of eight hours and others of 15 still others no fasting in effort to be efficient follow your doctor's orders regarding fasting and npo status nothing by mouth including water before blood tests. Prior to a blood test it is common that fasting is required. It is done for 10 to 15 hours before the test is performed according to the doctor's advice. During the fasting the patient is not advised to take any food or drink other than water. Some blood tests will require you to fast beforehand. In these cases your doctor will instruct you not to eat or drink anything except water in the hours leading up to the test. Check with your doctor to ensure you understand the directions for your blood tests. If you don’t properly fast your test results could lead to an incorrect diagnosis and the need to repeat the blood test. Some people find it difficult or even unsafe to do fasting lab tests. For example people taking insulin to manage their diabetes may be at risk for low blood sugar if meals are delayed or missed. If you have any difficulties fasting due to transportation or health issues ask your doctor about alternative tests that do not require fasting.