Test guide
Fasting for a Blood Test
If your health care provider has told you to fast before a blood test, it means you should not eat or drink anything, except plain water, for several hours before your test. While you're fasting for a blood test, you should also not :
What it is for
Source: MedlinePlus, National Library of Medicine. Medical test information is public domain. Source identity and definition checked automatically on 2026-10-18. No individual clinical interpretation or human reviewer is asserted.
Limitations
Reference intervals and interpretation depend on the laboratory, specimen, method and clinical context. This source definition is educational information; it does not establish a diagnosis, product approval or suitability for an individual.
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