Single marker guide · High-sensitivity CRP (hs-CRP)
C-reactive protein is the body's inflammation signal. The standard NHS CRP test is built to catch infections and flare-ups, so it only reads reliably above about 5 mg/L. The low-grade inflammation that drives heart disease, insulin resistance and unexplained fatigue lives between 0 and 3. That is what high-sensitivity CRP measures, it is what every TrueVitals panel includes, and it is the difference between "no infection" and "no inflammation".
Venous draw at 103 UK clinics or at home. UKAS-accredited laboratory. Report reviewed by a medical professional.
The short answer
CRP is made by the liver in response to inflammation anywhere in the body. When you have an infection or an autoimmune flare it can rise into the tens or hundreds, and the standard CRP test your GP orders is designed for that job: it reports anything under 5 or 10 mg/L as simply "normal" and stops there. That is fine for spotting pneumonia. It is useless for the question most people actually have.
High-sensitivity CRP measures the same protein with an assay that resolves down to a fraction of a milligram. In that range, a persistent reading of 2 or 3 mg/L is not an infection. It is the signature of low-grade, chronic inflammation: visceral fat releasing inflammatory signals, insulin resistance, poor sleep, gum disease, a chronically stressed immune system. That kind of inflammation is what turns a cholesterol particle into a plaque and a plaque into a heart attack, and it is why hs-CRP predicts cardiovascular events independently of cholesterol. Heart health blood test guide.
Reference ranges
| hs-CRP result | Category | What it means |
|---|---|---|
| Below 0.5 mg/L | Optimal | Minimal background inflammation. Where preventive clinicians aim, and where most lean, well-slept, metabolically healthy adults sit. |
| 0.5 to 1.0 mg/L | Low risk | The low cardiovascular risk band used by the American Heart Association. Nothing to act on in isolation. |
| 1.0 to 3.0 mg/L | Moderate risk | Low-grade inflammation is present. Very common, almost always lifestyle-driven, and reversible. Read alongside insulin, ApoB, waist and sleep. |
| 3.0 to 10 mg/L | High risk | Roughly double the cardiovascular event risk of the lowest band. Worth finding the source: metabolic, dental, autoimmune or a low-level infection. Repeat in a few weeks to confirm it is persistent. |
| Above 10 mg/L | Acute | Something active: a cold, an injury, a dental abscess, a flare. Not interpretable for cardiovascular risk. Retest two to three weeks after you are well; if it stays above 10, see your GP. |
Categories follow the American Heart Association and CDC statement on hs-CRP and cardiovascular risk. hs-CRP rises temporarily with any illness, injury, intense exercise, pregnancy and oestrogen-containing medication; TrueVitals reports account for what you tell us.
Where it comes from
hs-CRP does not tell you where the inflammation is. That is what the rest of the panel and your history are for. In practice the sources are predictable, and most of them are fixable.
Fat around the organs is metabolically active tissue that secretes inflammatory signals directly. Waist circumference predicts hs-CRP better than BMI, and losing visceral fat is the single most reliable way to bring it down. Can't lose weight guide.
High insulin and inflammation drive each other in a loop. A raised hs-CRP with a raised HOMA-IR is the metabolic syndrome pattern, and it is the one that responds fastest to changes in carbohydrate, movement and sleep. Prediabetes guide.
Short or fragmented sleep raises hs-CRP within days. So does sustained cortisol. If the metabolic markers are clean and hs-CRP is still 2, sleep is the first place to look. Stress blood test guide.
Periodontitis is one of the most common and most overlooked causes of a persistently raised hs-CRP, and treating it lowers CRP measurably. If your dentist has mentioned bleeding gums, that is your source.
Early autoimmune disease often raises hs-CRP before symptoms are obvious. Alongside thyroid antibodies, coeliac antibodies and immunoglobulins, a persistent 3 to 10 result can be the first clue. Autoimmune blood test guide.
Each raises hs-CRP on its own. Oestrogen-containing contraception and HRT can push it into the 1 to 3 band without any underlying problem, which is why we ask about medication before interpreting it.
Who should test
The cardiovascular case is settled: hs-CRP predicts events independently of cholesterol, and the JUPITER trial showed that people with a normal LDL but an hs-CRP above 2 cut their heart attack and stroke risk substantially with treatment. If you are testing ApoB and Lp(a), hs-CRP is the marker that tells you whether the particles you have are being turned into plaque. ApoB guide.
The less obvious case is fatigue, low mood and joint aches with normal thyroid, iron and B12. Persistent low-grade inflammation is exhausting in itself, and a raised hs-CRP alongside otherwise clean results turns "we can't find anything" into "here is the thing, now let's find its source". Always tired but tests normal?
Read it in context
hs-CRP tells you inflammation is present. The markers beside it tell you where it is coming from and what it is doing.
Particles cause plaque; inflammation decides whether plaque ruptures. High ApoB with high hs-CRP is the combination that most needs acting on, and low hs-CRP takes some of the urgency out of a moderate ApoB. All three are in Ultimate. Lp(a) guide.
If insulin is high, the inflammation is metabolic and the fix is metabolic. If insulin is normal, look elsewhere. Insulin and HOMA-IR are in Ultimate.
Ferritin rises with inflammation, so a raised hs-CRP means a "normal" ferritin may be hiding iron deficiency. Reading them together is the only way to trust either. Ferritin guide.
A raised white count with a high hs-CRP points to infection or an active flare; a normal white count with a mildly raised hs-CRP points to the chronic, metabolic kind. The full blood count in every panel makes that distinction.
A fatty liver is an inflamed liver. Raised ALT or GGT next to a raised hs-CRP usually means the source is the liver, and the treatment is the diet changes that reverse it. Liver guide.
A silent urinary infection, an immune system working overtime, or undiagnosed coeliac disease all raise hs-CRP and all show up on these Ultimate markers. Homocysteine and ESR in the Signature panel add two further inflammatory angles.
Which test
Advanced
74 biomarkers · £269
hs-CRP with ApoB, full lipids, HbA1c, liver enzymes, full blood count, ferritin and iron studies, full thyroid, vitamin D and hormones. The right choice for a first cardiovascular and inflammation baseline.
View AdvancedMost chosen
Ultimate
114 biomarkers · £349
Everything in Advanced plus Lp(a), fasting insulin and HOMA-IR, immunoglobulins, coeliac screening and urinalysis, the markers that locate the source of a raised hs-CRP rather than just reporting it.
View UltimateSignature
230 biomarkers · £799
Processed by Randox. Adds ESR, homocysteine and extended autoimmune, cardiovascular and digestive screening. The deepest inflammatory picture available privately in the UK.
View SignatureClinic draw £19 at 103 UK clinics. At-home phlebotomist £39 across 200+ areas. Fast from 10pm the night before. Pay monthly available.
Honest comparison
If you have a known inflammatory condition and are monitoring a flare, a standard CRP from your GP is the right test and it is free. If you want to track hs-CRP after changing your lifestyle and already have a full picture from a recent panel, a standalone hs-CRP from Medichecks costs around £39 and does the job. Make sure it says high-sensitivity; a standard CRP will simply report "under 5" and tell you nothing.
A panel is the better choice for a first look, because a raised hs-CRP on its own is a question, not an answer. Whether it is metabolic, dental, autoimmune, hepatic or infectious comes from the markers around it, and that is what decides what you do next. See how every UK provider compares.
After the result
Background inflammation is low. If ApoB or Lp(a) is high, that is still worth acting on, but the inflammatory multiplier is not present. Retest with your next panel.
Look at the rest of the report for the source: insulin, waist, liver enzymes, sleep, gums. The interventions that reliably lower hs-CRP are losing visceral fat, seven hours of sleep, a Mediterranean-style diet with oily fish, regular exercise, and treating gum disease. Expect movement within three months.
Retest in two to three weeks to rule out a passing illness. If it is persistent, take your report to your GP: it raises cardiovascular risk enough to change the conversation about ApoB treatment, and it may warrant looking for an autoimmune, dental or infectious source. Above 10 that GP conversation should happen sooner.
This page is general information, not medical advice. A very high CRP with fever, severe pain or feeling acutely unwell needs same-day medical attention.
FAQs
Same protein, different assay. Standard CRP is calibrated for infection and inflammatory disease and reads reliably only above about 5 mg/L. High-sensitivity CRP resolves down to around 0.1 mg/L, which is the range where chronic low-grade inflammation and cardiovascular risk live. Every TrueVitals panel uses the high-sensitivity assay.
Below 1 mg/L is low cardiovascular risk, 1 to 3 is moderate, and above 3 is high, per the American Heart Association. Above 10 suggests an acute process and should be repeated once you are well. Preventive clinicians generally aim for below 1, and ideally below 0.5.
Acutely: infection, injury, surgery, intense exercise, a flare of an inflammatory condition. Chronically at low levels: visceral fat, insulin resistance, poor sleep, smoking, gum disease, alcohol, oestrogen-containing medication, early autoimmune disease and fatty liver. The markers around hs-CRP in a panel usually point to which.
Rarely. NHS practice uses standard CRP to look for infection and inflammatory disease, and reports results under 5 as normal. hs-CRP for cardiovascular risk is not part of the NHS Health Check. A private panel includes it as standard. What to ask your GP for.
Yes, and it usually responds within weeks to months. Losing visceral fat, sleeping seven hours, exercising regularly, eating a Mediterranean-style diet with oily fish, stopping smoking, moderating alcohol and treating gum disease all lower hs-CRP. Statins lower it too, which is part of why they reduce events even in people with normal cholesterol.
Not for CRP itself. TrueVitals panels also include glucose, insulin and triglycerides, so we ask you to fast from 10pm the night before and drink water as normal. Avoid intense exercise for 48 hours beforehand, which raises CRP on its own.
Better to wait. Any infection pushes CRP up for two to three weeks and makes the cardiovascular reading meaningless. Rebook once you have been well for a fortnight. The same applies to a recent injury, dental work or vaccination.
A standalone hs-CRP test is around £39. A TrueVitals Advanced panel is £269 and includes hs-CRP with ApoB, full lipids, HbA1c, liver, ferritin, a full blood count and 65 other markers; Ultimate at £349 adds Lp(a), fasting insulin, immunoglobulins and urinalysis, the markers that find the source.
74 to 230 biomarkers. Venous draw at 103 UK clinics or at home. A report that tells you what your results mean and what to do next.
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