On the NHS, you may get your blood test results after a few days, and usually within a few weeks (NHS). Many common tests are actually analysed within hours of reaching the lab, so most of the wait is transport, a clinician reviewing the result, and getting it back to you. Timings vary by test, lab and service.
Key takeaways
- NHS results usually come within a few days to a few weeks (NHS).
- Common tests are often ready in the lab within hours; specialist tests sent to another lab can take days or weeks (Leeds Teaching Hospitals NHS Trust).
- No news isn't always good news. Some GP surgeries only contact you if they need to discuss a result, so check the NHS App or ask (NHS).
- Most blood tests don't need fasting, but some, such as a fasting glucose test, do. Always follow the instructions you're given.
NHS vs private: typical timings
These are typical examples only. Your own wait depends on the test, the lab's workload and how results reach you.
| Test | In the lab | Typical NHS wait for you | Private example |
|---|---|---|---|
| Full blood count (FBC) | Routine sample within 2 hours at one NHS lab (Gloucestershire Hospitals) | A few days to a few weeks (NHS) | Listed as 1 day by one private lab (TDL) |
| Cholesterol (lab sample) | Varies | A few days (NHS) | Varies by provider |
| HbA1c (diabetes test) | Varies | A few days (NHS) | Listed as 1 day (TDL) |
| Finger-prick cholesterol | A few minutes on the machine (NHS) | Same appointment | Same appointment |
| Specialist tests sent away | Days or weeks (Leeds Teaching Hospitals) | Longer | Longer |
Lab turnaround times are counted from when the sample arrives, so allow for posting or courier time and for a clinician to review the result.
Why some results take longer
Hospital labs describe turnaround as "very variable", depending on which tests were requested (Royal United Hospitals Bath). Common reasons for a longer wait:
- the sample has to go to a specialist laboratory
- your doctor needs time to receive, review and interpret the result
- your surgery only contacts you if something needs discussing (NHS)
Labs can't give results directly to patients: contact the GP or clinician who requested the test (Leeds Teaching Hospitals; RUH Bath). You may also be able to see NHS results in the NHS App or your NHS account (NHS).
What common blood tests show, and whether to fast
| Test | What it checks | Fasting usually needed? |
|---|---|---|
| Full blood count (FBC) | Red cells, white cells and platelets, as a general health check (Lab Tests Online UK) | No |
| Urea and electrolytes (U&E) | Kidney function and salts such as sodium and potassium (Lab Tests Online UK) | Follow your instructions |
| Liver blood tests | Enzymes and proteins made by the liver (Lab Tests Online UK) | No |
| Cholesterol | Blood fats linked to heart risk (NHS) | Most people don't, but you may be asked to fast for up to 12 hours |
| HbA1c | Average blood sugar over 2–3 months (Lab Tests Online UK) | No |
| Fasting glucose | Blood sugar, to screen for diabetes (Lab Tests Online UK) | Yes, usually 8–10 hours, water allowed |
| Ferritin | Your body's iron stores (Lab Tests Online UK) | Sometimes, for up to 12 hours |
For what the numbers mean, see our guides to the HbA1c blood test and thyroid blood test results.
How to prepare for a blood test
The person arranging your test should tell you about any preparation (NHS). In general:
- Fasting means nothing to eat or drink except water. For most fasting tests that's at least 8 hours, and samples are usually taken in the morning. If you eat by mistake, tell whoever takes your blood, as it affects the result (RUH Bath).
- Medicines: you may be asked to stop some, such as medicines that help prevent blood clots, for a short time. Only stop a medicine if you've been told to (NHS).
- Supplements: very high doses of biotin can give incorrect thyroid results, so mention any supplements you take (British Thyroid Foundation).
- On the day: the test itself takes about 10 minutes. You may get some bruising or swelling, which should go away after a few days (NHS).
Renvo can help. Our London clinic offers blood tests in person, and a clinician explains what your results mean and what, if anything, to do next. blood tests at our London clinic
When to see a GP
- If you haven't heard about a result you were expecting, don't assume it's normal. Check the NHS App or contact your surgery (NHS).
- If a clinician tells you a result needs follow-up, book that appointment promptly.
- If your symptoms get worse while you're waiting, don't wait for the result: contact your GP or NHS 111.
- Call 999 in an emergency, such as severe chest pain or difficulty breathing.
If you are considering paying for testing rather than waiting, our guide to private blood tests in the UK sets out what panels cost, what they include, and how to check whether you can get the same test free first.
If you are considering IV vitamin therapy, our guide to IV drips in the UK explains when intravenous delivery genuinely helps and when a blood test is the better first step.
Honest FAQs
How long do NHS blood test results take?
Usually a few days, and within a few weeks. Some specialist tests take longer because they're sent to another lab (NHS; Leeds Teaching Hospitals).
Does no news mean my blood test is normal?
Not always. Some GP surgeries only contact you if they need to discuss a result, so check the NHS App or ask your surgery (NHS).
Can I drink water before a fasting blood test?
Yes, usually. Fasting means nothing to eat or drink except water, unless you've been told otherwise (NHS).
Are private blood test results faster?
Often. Some private labs list a 1-day turnaround for routine tests such as a full blood count, once the sample arrives (TDL). Timings vary by provider.
This article is general information, not medical advice. Always speak to a qualified clinician about your own symptoms.
