Lab tests | 3 min read
Fasting for a blood test: what you can and cannot do
Which tests need fasting, how long to fast and whether you can drink water or take your medicines.
By Lab team, City Care Clinic (demo)
Some blood tests give a correct result only on an empty stomach. Others do not need fasting at all. Here is a simple guide.
Tests that usually need fasting
- Fasting blood sugar: 8 to 10 hours
- Lipid profile (cholesterol): 9 to 12 hours
Tests that do not need fasting
- CBC
- HbA1c
- Thyroid (TSH)
- Urine routine
During the fast
Plain water is fine and helps the sample. No tea, coffee, juice, chewing gum or smoking. Ask your doctor before stopping any medicine, especially for diabetes or blood pressure.
After the sample
Eat something soon after the sample, especially if you have diabetes. Bring a small snack with you.
Sample article on a demo website, for general information only. It is not medical advice: always ask your own doctor. In an emergency call 1122.