Inflammation and heart health
Normal CRP Levels: Under 5, and What Yours Means
Reviewed by a qualified clinician · analysed at UKAS-accredited UK labs (ISO 15189)
Last reviewed August 20266 min read
Every Helvy guide is written by our health editors, then checked by a qualified clinician before it goes live and re-checked as the science moves. We name clinical roles, not individuals, until each reviewer has agreed to be credited publicly. This is wellness guidance to help you understand your own data, not a diagnosis.
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UK labs report CRP as normal below 5 mg/L. Between 5 and 10 sits just outside, and often means very little on its own. Above 10 usually means real inflammation somewhere. The number tells you how much, never where or why. hs-CRP is a separate test, read against much smaller numbers.
Not sure which markers you need? Build your test →Your CRP comes back at 7. The range on the report stops at 5. You feel fine, you had a cold a fortnight ago, and now you are reading about inflammation at eleven at night.
CRP stands for C-reactive protein. Your liver makes it, and it climbs fast whenever something is inflamed. That speed is what makes it useful. It is also why a single number rarely settles anything.
1. What is a normal CRP level in the UK?
Below 5 mg/L. One range covers every adult age, and UK laboratories agree on it closely. Pathology services at Gloucestershire Hospitals, North Bristol and Worcestershire Acute Hospitals all publish the adult reference range as under 5 mg/L.
| Result | How it reads |
|---|---|
| Under 5 mg/L | Inside the reference range. |
| 5 to 10 mg/L | Just outside. Often a recent bug or a minor injury. |
| 10 to 100 mg/L | Something is inflamed. Worth a GP conversation. |
| Above 100 mg/L | A strong response. Usually needs same-week medical review. |
Those upper bands come from how the NHS uses the number in practice. In NICE guideline CG191, a GP assessing a chest infection is advised not to routinely offer antibiotics below 20 mg/L, to consider a delayed prescription between 20 and 100, and to offer treatment above 100. The number sets the weight of the response, not the diagnosis.
2. Why your CRP number cannot name the cause
This is the part worth understanding before you read anything else into your result. CRP is one protein your liver releases in response to inflammation anywhere in the body. A sprained ankle, a chest infection and an inflamed joint all raise it. The NHS laboratory that publishes the range says so directly.
“As CRP is a non-specific marker of inflammation, it does not indicate the organ or organs affected.”
— Gloucestershire Hospitals NHS Foundation Trust pathology
So a CRP of 7 does not point anywhere. What it does is set a question. The same laboratory notes that CRP responds faster than the older inflammation tests, which is why it gets used to track whether something is settling. One reading is a snapshot. Two readings a month apart are an answer.
3. hs-CRP is a different test with different numbers
People mix these up constantly. hs-CRP means high-sensitivity CRP. It measures the same protein, but it can read the very low concentrations a standard CRP assay simply reports as under 5. That precision is used for a different job: describing cardiovascular risk rather than hunting for an infection.
The CDC and the American Heart Association set the bands that most laboratories still use. A review in the Journal of the American College of Cardiology summarises them as under 1 mg/L, 1 to 3 mg/L, and above 3 mg/L. Those map to lower, average and higher risk.
Two things follow from that. If your CRP reads 12 because you have a sore throat, the hs-CRP bands mean nothing that week. And the same review notes that levels vary enough between days that repeat testing is recommended for any value above 5 mg/L, with a high result worth rechecking at least a month later.
If heart risk is your actual question, hs-CRP earns its place beside your cholesterol breakdown rather than on its own.
4. What lifts CRP when you are not ill
A mildly raised result is common, and the usual explanations are ordinary:
- A cold, sore throat or stomach bug in the past two weeks.
- A hard training session, a fall, or recent dental work.
- Carrying extra weight, which keeps a low background level up.
- Smoking.
- Pregnancy, and some hormonal contraception.
- A long-term inflammatory condition already known about.
None of that makes a raised CRP safe to ignore. It makes timing worth checking first. If you tested within a fortnight of being unwell, a repeat once you are properly better tells you far more than reading about the first number.
There is one pattern that does deserve attention. A CRP that stays up across two tests, weeks apart, when you feel perfectly well, is different from a single raised reading. It is not a diagnosis of anything. It is a reason to take the pair of results to a GP rather than wait for a third.
Some medicines also pull the number down. Anti-inflammatories and steroids can lower CRP without changing whatever caused it. Statins do the same. If you take any of those, say so when your result is being read, because a normal CRP means less against that background.
5. Which blood test reports your CRP
The marker is C-reactive protein, reported in mg/L. No fasting is needed. Take the sample when you are well, or the number will describe last week rather than this year.
Helvy's General Energy & Wellness panel (£149) reports CRP alongside thyroid, kidney, cholesterol, cortisol and vitamin markers. That grouping is the point. A raised CRP on its own asks a question, and the markers around it are what start answering it.
If your question is specifically about heart risk, our Advanced Heart Health panel (£159) reports hs-CRP instead, next to ApoB, Lp(a), HbA1c and the full lipid breakdown. To work out which set fits your situation, the build-my-test tool walks you through it.
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Helvy's home blood tests report CRP with plain-English context, and with the thyroid, kidney and cholesterol markers a raised result sends you looking for. Samples are processed by UKAS-accredited UK labs.
Frequently asked questions
What is a normal CRP level in the UK?
Under 5 mg/L. Gloucestershire Hospitals, North Bristol and Worcestershire Acute Hospitals NHS pathology services all publish that adult reference range. The same figure applies at every adult age. Read your number against the range printed on your own report, since laboratories vary slightly.
Is a CRP of 7 something to worry about?
It is just outside the reference range, and on its own it rarely means much. A cold, a heavy training session or dental work in the past fortnight will do it. The useful step is a repeat once you are properly well, not a search for meaning in the first number.
What CRP level is considered high?
Above 10 mg/L usually means something is genuinely inflamed and is worth a GP conversation. NICE guideline CG191 treats over 100 mg/L as high enough to offer antibiotic treatment for a suspected chest infection. A CRP that high needs medical review rather than a home interpretation.
Can a blood test tell you where the inflammation is?
Not from CRP. NHS pathology states that CRP is a non-specific marker and does not indicate the organ or organs affected. It measures how much of a response your body is mounting. Finding the source needs your symptoms, your history and other tests read together by a qualified clinician.
What is the difference between CRP and hs-CRP?
Same protein, different sensitivity. Standard CRP is used to spot and track inflammation and reports below 5 mg/L as normal. hs-CRP reads the much smaller numbers underneath that, and is used to describe cardiovascular risk against bands of under 1, 1 to 3, and above 3 mg/L.
Do you need to fast before a CRP test?
No. CRP is not affected by a recent meal. Timing still matters for a different reason. Test when you are well, because a bug or an injury in the previous two weeks can leave the number raised and make it hard to read.
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