Some blood tests require you to fast for several hours beforehand, usually about 8-12 hours before the blood sample is collected. Of course, you shouldn’t eat or drink anything during that fasting period. But is that all?
Smoking can affect your blood test results. So if you have been asked to fast before your blood test, you should avoid smoking as well. Other things to avoid before the test include:
Unless your doctor advises you to do otherwise, you should be able to take your usual prescription medications.
Why is it important to fast before a blood test?
Fasting is not mandatory for kidney function tests, testing vitamin levels in the blood, blood markers test, etc.
But for some blood tests, fasting beforehand helps improve the accuracy and reliability of the results. And accurate test results are essential for diagnosing various health conditions and monitoring the effectiveness of treatment.
When you eat and drink before blood tests, the nutrients you consume are broken down and absorbed into your bloodstream. This can increase the levels of certain substances in your blood, such as blood sugar, iron, cholesterol, triglycerides and enzymes, which affect the results of the test and could lead to an incorrect diagnosis and health complications.
Sometimes, you may forget about the fast and accidentally eat or drink something. If this happens, you should talk to your doctor about rescheduling the blood test.