Preparation guide
Fasting Before Laboratory Testing
Fasting means avoiding food and most drinks for a specified period when the requested test requires it; water may be allowed under the supplied instructions.
Why is this important?
Understanding the purpose and limits of laboratory information can support a more informed conversation with a qualified healthcare professional.
How laboratory testing relates
Some laboratory tests require fasting and many do not. Confirm the exact duration and whether water is permitted for the ordered test.
Before testing
Preparation is test-specific. Follow the instructions given for the exact test and contact the laboratory if fasting, timing, medicines, or specimen collection is unclear. Do not stop medicines unless a qualified professional tells you to.
Educationally related laboratory guides
These links explain related laboratory records. They are not recommendations to request or purchase a test.
Sources & further reading
- MedlinePlus, U.S. National Library of Medicine: Fasting for a Blood Test
External authoritative patient reference · Verified 2026-08-10
- MedlinePlus, U.S. National Library of Medicine: How to Prepare for a Lab Test
External authoritative patient reference · Verified 2026-08-10
Prefer collection at home?
Request Home Collection and our laboratory team will confirm the requirements and appropriate arrangements.
Request Home Collection