Frequently asked questions about

Fasting Guidelines

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Fasting before your Blood Test

Welcome to JACE Medical’s Frequently Asked Questions section. We understand that you may have questions regarding your upcoming blood test, so we have provided answers to some common questions below.

Fasting FAQs

Do I need to fast before I have a blood test?

For some blood tests, it is necessary to fast overnight before the blood samples are collected in the morning. Fasting means you cannot eat anything and can only drink water. Tea, coffee, and cola can affect some blood results, so even black coffee and sugar-free drinks must be avoided. Chewing gum or smoking must also be avoided on the morning of the test.

Fasting guidelines

Please follow the fasting guidelines for the following blood tests:

  • Fasting glucose: fast for at least 8 hours.
  • Oral glucose tolerance test: fast for at least 8 hours. Note that this test takes a minimum of 2 hours, during which you must sit quietly and not eat or smoke.
  • Lipids/triglycerides/fasting cholesterol: fast for at least 10-12 hours.
  • Cholesterol: Fasting is not essential when the test is requested for screening or monitoring, but it may be recommended for diagnosis.
What if I am diabetic?

Fasting lipid results are rarely needed in diabetic patients. If you are diabetic, DO NOT fast before this test and do not stop taking or change your existing medication.

What if I have to take medicine in the morning?

Do not alter your medication unless instructed to do so by your doctor. If your medicine needs to be taken with food and this will interfere with the timing of your fasting blood test, please discuss this with your doctor.

More information

For more information about blood tests, click here. This website can help you understand the many tests that are part of routine care, as well as diagnosis and treatment of a broad range of conditions and diseases.

We hope you find this information useful, and please do not hesitate to contact us if you have any further questions or concerns.