Some blood tests will require fasting in advance. In this case, your doctor will instruct you not to eat or drink anything other than water within a few hours of the test. It is important to fast before some blood tests to make sure your blood test results are correct. The vitamins, minerals, fats, sugars and proteins that make up food and drink can confuse your test results and affect your blood sugar levels.
When do you need be on fasting?
It is not necessary be on fasting before every blood test. You may need to fast for blood tests which include:
- Blood glucose testing
- Liver function testing
- Cholesterol testing
- Triglyceride level test
- High-density lipoprotein (HDL) level test
- Low-density lipoprotein (LDL) level test
- The main panel of metabolism
- Kidney function Lipoprotein panels
Ask your doctor if he or she has a new blood test for you, or if you need to fast or if you can’t figure out how long, you should fast. Some tests, such as bowel movements, do not require fasting, but do limit certain foods. Red meat, broccoli and even some medications can cause false polo positive testing. Always follow the advice of your doctor when preparing for a test. However, Apart from knowing the rules and regulations, you need to choose the best lab near where you live. For instance, if you live in Hooghly, choose the best doctor clinic in Uttarpara, Hooghly for all your blood test needs.
How long should you fast before a blood test?
It totally depends on the kind of test you are having. “Make sure to not even have tea or coffee when you wake up” – says the lab experts of the pathology lab in Uttarpara, Hooghly.
Here are some specific guidelines to keep in mind while undergoing a blood test in Uttarpara, Hooghly.
1) For Blood Glucose “Fasting”: 8 to 10 hours fasting is suggested. Nothing can be taken except water, even those who are habituated in smoking, no smoking before giving the blood sample.
2) For Blood sugar “PP“: Sample (blood) is to be given just after 2 hours before meal, not 2 hrs after finishing meal.
2) For Lipid Profile (HDL, LDL Triglycerider, Cholesterol): Experts suggest 12 to 14 hours of fasting – especially in case of Blood sugar Fasting. Further, in the 3 nights before giving blood sample for Lipid Profile, you should avoid rich food such as red meat, chicken, fat, ghee, butter etc.
3) Complete Haemogram /CBC: Fasting is necessary for ESR result.
4) For Lithium level test: Those who are taking medicine for Lithium, sample (blood) is to be given after 12 hrs of taking medicine.
5) For Thyroid or TSH test: Those who are taking medicine for thyroid, sample (blood) is to be given after 12 hrs of taking medicine.