Home Health information Why do you need to fast before checking your health?
Why do you need to fast before checking your health?

Why do you need to fast before checking your health?


Have you ever had a medical check-up? Medical check-up is a comprehensive medical examination that aims to determine the patient's health condition. This health check can be done for all ages and genders depending on one's needs. You can check your health anywhere as long as there is a laboratory available for blood tests.

Usually before conducting a blood test, the doctor will tell the patient to fast. But there are also certain types of health checks where the doctor allows you to eat and drink whatever you want.

Proper preparation of the examination is something that you need to do in order to get accurate examination results as a form of diagnosis related to the medical problem you are experiencing. That is why, you must carry out instructions given by the doctor correctly to avoid re-examination or avoid unnecessary additional examinations.

Why fasting first before having a health check?

Fasting before a health examination is very important to help ensure that your test results are accurate. Because the nutritional content in food and drinks that you consume before conducting a health test will be absorbed into the bloodstream and can have a direct impact on blood glucose, fat and iron levels in the body.

That is why you are instructed by your doctor to fast before taking a medical. This is also a way to ensure that the results of the examination are not affected by recent food consumption and can be interpreted correctly by the doctor so that the diagnosis process related to your health condition will be more accurate.

The type of test that requires fasting before a health check

Some health checks that require patients to fast during medical check-ups, namely:

  • Glucose check
  • Cholesterol check (lipid / fat profile)
  • Urea and uric acid examination
  • Examination of liver function
  • Triglyceride level check
  • Check the basic metabolic system
  • And so forth

How long do you have to fast before checking for health?

Basically, the length of your fast depends on the type of health test you are doing. Fasting time is around 10-12 hours before taking a health test. But if you want to check glucose levels in the blood, you are advised to fast enough for at least 8 hours.

What are the consequences if not fasting before a medical check-up?

Fasting in the context of a health check is not to consume food and drinks within a predetermined time period. Even so you are still allowed to drink water so that the body remains well hydrated so that it will give a picture of the actual examination level.

Well, if you are not fasting or fasting is not according to the recommended time, the examination that you do will give inaccurate results because certain checks are still influenced by food. But if you feel fasting will only cause problems for the condition of the body, you can consult your doctor or nurse.

Can I take medicine when doing a health check?

Before you do a health check, you are not allowed to take drugs for a certain period of time. Because there are several drugs that will have an impact on blood test results. But if it is required to continue taking the drug, it helps you make confirmation to the laboratory. This aims to assist the laboratory in validating your health test results.

Also Read:

  • 5 Surefire Tricks Overcoming Fear Check Health
  • Why Do We Have to Fast Before the Operation?
  • Benefits and Risks of Fasting for Health

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Reviewed date: May 29, 2017 | Last Edited: May 29, 2017


What to know about fasting before your lab test - http://www.questdiagnostics.com/home/patients/prepare-for-test/fasting.html diakes on May 24, 2017

Everything You Need to Know About Fasting Before a Blood Test - http://www.healthline.com/health/fasting-before-blood-test accessed on 24 May 2017

Can I Eat and Drink Before Having a Blood Test? - http://www.nhs.uk/chq/Pages/1018.aspx?CategoryID=69 accessed on May 24, 2017