Labs & Reports · Inflammation markers

CRP Test: Normal Range, What a High CRP Means, and Price in India

Written by · Registration TSMC/FMR/36195 · Published: 16 September 2026 · 23 min read · 19 references
Minimalist illustration of a round white ceiling smoke detector with a single red light on a cream background, a thin wisp of grey smoke drifting up towards it.
CRP is the body's smoke alarm. It registers that something is burning somewhere in the house, and roughly how strongly, which is why a single number can be raised by an infection, a flare of arthritis or the fourth day after an operation. It cannot tell you which room, and it cannot tell you whether the smoke is a fire or the toast.

A CRP test measures C-reactive protein, a protein your liver releases when there is inflammation anywhere in the body. About 90 percent of healthy young adults have a CRP under 3 mg/L, and labs set their upper limit at 3, 5 or 10 mg/L. A level over 10 mg/L is a clear rise. Above 100 mg/L is a marked rise that raises suspicion of a significant infection or another major inflammatory or tissue-injury process.12 In India the standard test costs about ₹250 to ₹620 at a national chain.3

Think of it as a thermometer for inflammation, one that reads the whole body at once and reports a single number that any lab can measure for a few hundred rupees within a day. The number tells you how much inflammation there is. It never tells you where, and it never names the cause on its own. A CRP of 40 can be a chest infection, a flare of rheumatoid arthritis or the fourth day after an operation. This page gives you the ranges, what each band usually means, how fast the number moves, and the one thing to check before you read any of it: the unit your lab used.

What is a CRP blood test? Copy link

A CRP blood test measures the concentration of C-reactive protein in a sample of blood, usually taken from a vein in the arm. CRP is made almost entirely by the liver, on a signal from an immune messenger called interleukin-6, whenever tissue is injured, infected or inflamed.1 It belongs to a family of proteins called acute phase reactants, meaning proteins that rise sharply in the first hours of an illness.4

Doctors order it to check whether an inflammatory process is going on, to judge how large it is, and to watch whether it is settling with treatment. Typical reasons include fever with no obvious source, suspected bacterial infection or sepsis, monitoring after surgery, and tracking conditions such as rheumatoid arthritis, lupus and inflammatory bowel disease.5 The test needs no fasting and no preparation, although some Indian labs still print a fasting note on the booking page.23

Look for it on your report. You will usually see CRP as one line, often ordered with a complete blood count in the same draw. It is a separate tube from the CBC and is usually not part of a basic full body checkup package unless you ask for an inflammation add-on.

CRP normal range Copy link

There is no single normal CRP range. What the data give you is a distribution. In a study of healthy young blood donors the median CRP was 0.8 mg/L, 90 percent had a level under 3 mg/L, and 99 percent were under 10 mg/L.1 Labs print different upper limits, and Indian reports show this plainly, because one national chain marks anything under 10 mg/L as normal while another puts the line at 3 mg/L.36 Both are defensible, since the 10 mg/L line is the 99th centile in healthy people while the 3 mg/L line is where 9 in 10 healthy people sit.

CRP test result scale: under 3 mg/L is where about 90 percent of healthy adults sit, 3 to 10 a minor rise, 10 to 100 a moderate rise, over 100 a marked rise A horizontal four-segment scale for a CRP blood test result in mg/L with joints at 3, 10 and 100. The first segment, 0 to 3, is where about 90 percent of healthy adults sit, with the median healthy value of 0.8 marked. The next segments are labelled minor rise, moderate rise and marked rise. A note states that above 500 mg/L about 9 in 10 cases are bacterial infection, and that segments are equal width so the scale is not linear. CRP TEST · YOUR RESULT ON THE SCALE Where a CRP result sits 3 10 100 0 mg/L Where 90% of healthy adults sit Minor rise Moderate rise Marked rise Median healthy adult 0.8 Above 500 mg/L, bacterial infection in about 9 of 10 cases. Equal-width segments, so the scale is not linear. The interval on your report comes first. Pepys 2003 · StatPearls 2025 · refs 1–2
Plate 1. Where a CRP result sits, in mg/L. The first segment, under 3, is where about 90 percent of healthy adults sit, with the median healthy value of 0.8 marked; the joints at 10 and 100 separate minor, moderate and marked rises. Segments are equal width, so the scale is not linear. Pepys and Hirschfield (2003); Singh, Goyal and Patel, StatPearls (2025). References 1 and 2.
CRP levelUsual interpretationCommonly seen with
Under 3 mg/LWhere about 90 percent of healthy adults sitUsually no significant inflammation, with the exceptions listed later on this page12
3 to 10 mg/LMinor rise; may be normal for youObesity, pregnancy, diabetes, a common cold, gum disease, smoking, an inactive lifestyle2
10 to 100 mg/LModerate rise; active inflammationRheumatoid arthritis and other autoimmune disease, cancers, heart attack, pancreatitis, bronchitis; CRP can stay low in active lupus2
Over 100 mg/LMarked riseAcute bacterial infection, some viral infections, vasculitis, major trauma2
Over 500 mg/LSevere riseAcute bacterial infection in about 9 of 10 cases2

Bands from StatPearls (2025), converted from mg/dL to mg/L. Reference 2.

The CRP normal range does not change much with sex or age in the way hemoglobin does, but the baseline drifts up slowly through adult life, and women run slightly higher than men.15 Each person also has a fairly stable baseline of their own. Measured years apart, a person's CRP correlates about as well with itself as their cholesterol does.1 So a value of 4 mg/L that is the same every year is your usual baseline, and a value of 4 that was 0.6 last year is a change. A persistent baseline in that band is still worth knowing about, because it carries meaning for heart and metabolic risk, covered below.

CRP in mg/L or mg/dL: check the unit before the number Copy link

CRP is reported in two different units, and they differ by a factor of ten. One milligram per deciliter equals ten milligrams per liter. A result of 0.8 in mg/dL is 8 mg/L. That sits inside the reference interval some labs print, although it is higher than the level seen in about 90 percent of healthy young adults. A result of 8 in mg/dL is 80 mg/L, which is a moderate rise.2 Most Indian labs use mg/L, and everything on this page is in mg/L. If your report says mg/dL, multiply by ten before you compare it with anything here.

This is the commonest way a CRP result gets misread, including on health websites. Several widely read pages print thresholds like "over 10 mg/dL is high" and "over 50 mg/dL is dangerous" next to advice written for mg/L values. In mg/L those figures would be 100 and 500. If a page mixes the two units, close the tab.

You may also meet the unit problem in a second form. Small labs still run a latex slide test that only reports "positive" or "negative", sometimes with a titer. In the ASI kit cited here, the slide test detects CRP at or above 6 mg/L, and a titer is multiplied by 6 to give an approximate level, so a titer of 1:8 means roughly 48 mg/L; other kits use their own sensitivity and calculation.7 A "CRP positive" on such a report means the kit's detection limit was crossed and nothing more precise. Ask for the quantitative test if the number matters.

What does a high CRP mean? Copy link

Inflammation. Somewhere. That is all a high CRP means on its own, and how high it is narrows the likely cause. Between 10 and 100 mg/L the usual drivers are autoimmune disease, tissue injury and moderate infections. Above 100 mg/L infection becomes the most common single explanation, although major non-infectious inflammation produces the same numbers. A Canadian hospital series followed 839 adults with a CRP above 100 mg/L, and found infection behind 55 percent, rheumatologic disease behind 7.5 percent, cancer behind 5 percent, and no diagnosis at all in 18 percent despite a full work-up. Above 350 mg/L, 89 percent had an infection of some kind, bacterial or otherwise.8 The authors could not find any CRP level that excluded the non-infectious causes, the study is retrospective and from one center, so read the proportions as a rough map.

The test cannot tell bacterial from viral on its own. Among adults seeing a family doctor with a chest infection, about 74 percent have a CRP under 20 mg/L. About 23 percent sit in the 20 to 100 mg/L gray zone. Only about 3 percent are above 100. That is the band where a severe bacterial infection becomes likely.9 Most viral illnesses sit in the first group. Most bacterial ones do too. The overlap in the middle is wide, which is why the number is read next to your temperature, your symptoms and your white cell count.

High CRP also follows non-infectious injury. A heart attack produces a large CRP response that peaks around 48 hours and tracks the size of the damage.1 CRP also rises after major surgery. In uncomplicated recovery it peaks on the second or third day and then falls, returning to normal over about three weeks, and how high it goes depends on the operation.10 A level that stays high or rises again after that peak is one of the signals surgeons use to look for a complication, and a low CRP helps rule one out.10

How high a CRP is worrying? What 10, 20, 50, 100 and 200 mean Copy link

You probably came here with an exact number, so here are the bands. Read them with your symptoms in mind.

A CRP of 5 to 10 mg/L

Usually a minor elevation, and seldom an acute inflammatory signal. This is inside what most labs call normal, and above the median of 0.8 in healthy young adults. On its own this is a minor rise that is common with excess weight, smoking, a cold, gum disease or the later months of pregnancy.2 Whether a persistent level in this band matters is unsettled; MedlinePlus states plainly that it is unclear whether a rise of 3 to 10 mg/L is a cause for concern.4

A CRP of 20 mg/L

Raised. Modestly. You have a definite rise. With a cough and a fever this is the gray zone where a viral infection and an early bacterial one both sit. Without any symptoms it is a reason to repeat the test in a week or two, once whatever caused it has passed, before chasing a cause.1

A CRP of 50 mg/L

This needs an explanation. Common answers are a bacterial infection, a flare of an inflammatory condition, or the days after an injury or operation.2 A doctor will want to examine you. The next tests depend on your symptoms, the examination and the context.

A CRP of 100 mg/L and above

A marked rise, and one that warrants prompt clinical interpretation. At this level infection becomes the most common single explanation, but vasculitis, major trauma, a flare of autoimmune disease and some cancers produce the same result.28 Whether you need emergency care depends on how you are, and CRP is a poor triage tool on its own. Difficulty breathing, confusion, fainting or low blood pressure, rapidly worsening illness, severe pain or very little urine are reasons for urgent assessment whatever the number says.5

A CRP of 200 to 500 mg/L

Severe inflammation. In the Canadian series, nearly 9 in 10 people above 350 mg/L had an infection of any kind; separately, StatPearls puts bacterial infection at about 90 percent of cases above 500 mg/L.82 People with values this high are usually already under care, and a result at this level should be interpreted by a doctor promptly, with the symptom list above deciding how fast.

How fast CRP rises and falls Copy link

Fast. CRP starts rising within hours of a trigger, is above 5 mg/L by about six hours, and peaks at around 48 hours. It falls with a half-life of about 19 hours once the stimulus stops completely, so if production stopped dead a level of 160 mg/L would drop to roughly 80 a day later and 40 the day after that.1 In real illness production usually tapers rather than stops, so the fall is slower than that arithmetic. The half-life itself is the same in every illness, which means the only thing that sets your CRP level is how fast your liver is making it, and that reflects how strong the inflammatory stimulus is right now.1

CRP test kinetics: above 5 mg/L by about 6 hours, a peak near 48 hours, then a fall with a half-life of about 19 hours once production stops A line chart of a single C-reactive protein response over five days after one inflammatory trigger. The level rises within hours, crosses 5 mg/L by about six hours, peaks near 48 hours, and then falls with a half-life of about 19 hours once the liver stops making it. A note says that in real illness production tapers so the fall is slower. Schematic, not to scale. CRP TEST · HOW THE NUMBER MOVES How CRP rises and falls 0 h 1 day 2 days 3 days 4 days 5 days Above 5 mg/L by about 6 h Peak near 48 h Half-life about 19 h once production stops One trigger, drawn to published timings. In real illness the fall is slower. The half-life is the same in every illness; only the rate of production changes. Pepys 2003 · ref 1 · schematic
Plate 2. The shape of a single CRP response after one inflammatory trigger: above 5 mg/L by about six hours, a peak near 48 hours, then a fall with a half-life of about 19 hours once the liver stops making it. In real illness production tapers, so the fall is slower. Schematic, drawn from the published kinetics. Pepys and Hirschfield (2003), reference 1.

Three practical things follow for you. A CRP taken in the first six hours of a fever can be normal even in a bacterial infection, because the liver has not caught up; a repeat the next morning is more informative.1 A CRP that is falling day on day supports the view that treatment is working, though it does not prove it.5 And a CRP that keeps climbing on antibiotics is a reason to question the diagnosis or the drug.1

The number does not swing with time of day and is unaffected by eating, which is why a fasting sample is unnecessary.1 Liver failure blunts the response, and so do the drugs that block interleukin-6, covered below; beyond those, very few medicines lower CRP unless they also treat the underlying cause.1

Does a CRP result tell whether antibiotics are needed? Copy link

Partly. You will find the evidence here is less tidy than the marketing. NICE, the English guideline body, has used three cut-offs since 2014 for adults with a lower respiratory tract infection when, after examination, it is still unclear whether antibiotics are needed. Its current guideline, NG237, updated in September 2025, keeps them. Above 100 mg/L, offer immediate antibiotics; between 20 and 100 mg/L, consider a back-up prescription to be used only if symptoms worsen; below 20 mg/L, do not routinely offer antibiotics.1112 The test is a support for the decision after a clinical assessment, and NICE places it after that assessment for a reason.

The trial evidence behind those cut-offs is positive. A 2022 Cochrane review of 12 trials found that using a finger-prick CRP result in the consultation reduced antibiotic prescribing, with one fewer prescription for every 9 people tested. Recovery at 7 and 28 days was no different, and neither were hospital admissions, though the review notes that events were too few to be sure on that point.13

The Indian data point in the opposite direction, which is the part worth knowing. In a 2025 randomized trial at a Maharashtra teaching hospital, 208 children with up to five days of fever were split between a point-of-care CRP test and usual care, and the CRP group received more antibiotics, 59 percent against 46 percent, a difference that held up statistically. Inside that group, 84 percent of children with a CRP over 20 mg/L got an antibiotic, and so did 46 percent of those at or below 20.14 A test can only reduce prescribing if a low result is allowed to stop a prescription. In that clinic it did not. The number went up. The trial was open-label and from one center, so it is a caution, and it applies to how the test is used, since the biology has not changed.

For you the useful reading is this. A 2023 expert guidance paper, written by European primary-care researchers and funded by a test manufacturer, uses the same three bands. Under 20 mg/L, antibiotics strongly discouraged. From 20 to 100, the examination decides and a delayed prescription is an option. Over 100, antibiotics strongly recommended and hospital considered.9 In an assessed chest infection, a CRP below 20 mg/L lowers the likelihood that antibiotics will help, but it does not rule out a bacterial infection, and CRP cannot reliably separate bacterial from viral illness on its own. A CRP over 100 with fever needs a doctor today. In between, the number is one clue among several, and you should expect your doctor to examine you before deciding.

Why your CRP can be high with no infection Copy link

A CRP that sits between 3 and 10 mg/L year after year usually reflects low-grade inflammation from the body itself rather than an illness. The strongest single association is body fat. Fat tissue is a major source of the interleukin-6 that drives CRP production, weight loss lowers CRP in step with the weight, and people with insulin resistance or diabetes run higher CRP levels independently of what they weigh.1

This matters for Indian readers for a measured reason. In a study of 1,025 healthy men aged 35 to 60 in the United Kingdom, half of Indian origin and half European, the Indian men had CRP levels 17 percent higher on average. The difference was accounted for by their greater central obesity and insulin resistance.15 The study was of migrants and is now two decades old. Treat it as a signal that a mildly raised baseline is common where deep abdominal fat is common, and that the fat is the thing to treat.

Other reasons for a mildly raised CRP with no infection, each documented in the literature:

  • Smoking, gum disease and periodontitis, which are local inflammation the test picks up.12
  • Combined oral contraceptive pills and oral hormone therapy after menopause, which raise baseline CRP without any tissue inflammation. Skin patches do not.1
  • Pregnancy, especially the later months.2
  • Poor sleep and insomnia.52
  • Sitting most of the day; people who move less have higher levels.2
  • Your genes. Twin studies show a large inherited component to the baseline, independent of age and weight.1

Depression and anxiety have been linked to higher CRP in many studies, but once age, sex, weight and medical conditions are accounted for the link largely fades.2 A raised CRP in someone with low mood is more likely to be about weight, sleep or smoking than about the mood itself.

When CRP stays low despite real disease Copy link

No. A normal CRP does not rule out inflammation, and you should know the exceptions. Systemic lupus is the best-known exception: it can be very active with a CRP that barely moves, and nobody knows why. The CRP response to a new infection in the same person stays intact, so in lupus a CRP that suddenly climbs is a prompt to look for infection before assuming a flare.14 Some people with rheumatoid arthritis also show less rise than their joints suggest.4

Two situations can blunt the signal. Tocilizumab and similar drugs that block interleukin-6 stop the liver making CRP, so a person on them can have a serious infection and a normal result.2 Advanced liver failure does the same thing for a simpler reason, because the liver is the only organ that makes the protein in any quantity.1 Steroids, anti-inflammatory painkillers and statins lower CRP by damping the inflammation itself; tell the doctor if you take any of them, since a result taken on them reads lower than the underlying state.52

hs-CRP test: the heart-risk read of the same protein Copy link

Same protein, finer ruler. An hs-CRP test measures the same C-reactive protein with a more sensitive assay that can read levels below 1 mg/L. The "high sensitivity" describes the laboratory method and nothing else; the protein is identical.1 It is used to estimate heart-disease risk in people who are otherwise well. The American Heart Association and the CDC set three population bands in 2003, and most Indian reports still print them: under 1 mg/L low risk, 1 to 3 mg/L average risk, over 3 mg/L high risk.162 A meta-analysis of studies to the year 2000 covered 1,953 coronary events. People whose baseline CRP sat in the top third had twice the risk of a future coronary event of those in the bottom third.1

Modern cardiology literature uses 2 and 3 mg/L for slightly different purposes. An hs-CRP of 2 mg/L or higher has been used as a risk-enhancing threshold, and it was the entry criterion for JUPITER, which randomized 17,802 apparently healthy adults with LDL cholesterol under 130 mg/dL and hs-CRP of 2 mg/L or higher to rosuvastatin or placebo. The statin cut hs-CRP by 37 percent, LDL by 50 percent, and major vascular events by 44 percent, and the trial cannot say which of the two reductions did the work.17 The 2025 American College of Cardiology scientific statement on inflammation recommends broad hs-CRP screening alongside LDL. In primary prevention it treats a single value above 3 mg/L, measured when you are not acutely ill, as a marker of increased inflammatory risk. A value above 2 mg/L matters most in people with established heart disease, where the statement calls it residual inflammatory risk and rates it at least as predictive of future events as LDL, even on a statin.18 That is a scientific statement from one college. The 2026 multisociety dyslipidemia guideline builds most decisions on the PREVENT-ASCVD risk calculator, a lipoprotein(a) measurement at least once in adult life, selective apoB testing and coronary calcium scoring, so hs-CRP adds to that assessment without replacing it.19

The bands only mean anything at your true baseline. The 2003 statement asked for two measurements, taken about two weeks apart in a metabolically stable person and averaged, and for any result above 10 mg/L to be repeated after a search for infection or inflammation.16 An hs-CRP of 8 taken during a cold says nothing about your arteries. Indian booking pages often ask for an overnight fast before hs-CRP; the protein is unaffected by eating, so the fast is a lab convention. The test itself does not need it.13

What hs-CRP does not do is replace cholesterol, blood pressure, smoking history or a diabetes check. Some cardiologists order it alongside a lipid profile in a person whose parent or sibling had a heart attack young, or when a decision about a statin is on a knife edge. Whether the result should change treatment on its own remains debated; StatPearls calls its poor specificity the main obstacle.2

CRP vs ESR: which test says what Copy link

ESR, the erythrocyte sedimentation rate, measures how far red cells settle in a tube in one hour, which makes it an indirect measure of inflammation, one that rises and falls slowly over days to weeks and is pushed about by anemia, age and pregnancy. CRP is direct, fast, and much less confounded by those, though its baseline still shifts with age, sex, weight and pregnancy.21 Doctors often order both. Because CRP usually changes faster than ESR, a raised CRP with a still-normal ESR can reflect something that started in the last few days, and a raised ESR with a normal CRP something slower. Those are teaching heuristics; disease-specific biology and the non-inflammatory influences on ESR also produce mismatched pairs.4

Elevated ESR and CRP with joint pain is the pattern that gets people referred to a rheumatologist. ESR and CRP in rheumatoid arthritis are both used to check for flares and to see whether treatment is working.4 Persistent CRP elevation is typical of inflammatory arthritis, and the level tends to track how active the joints are.2 Two cautions apply. Some people with rheumatoid arthritis run a lower CRP than their joints would suggest, so a normal result does not exclude the diagnosis.4 And a mildly raised CRP with joint pain is far more often osteoarthritis, an injury or excess weight than an autoimmune disease. The rheumatoid factor and anti-CCP antibody tests, together with the pattern of joints involved, do the separating.

CRP test price in India Copy link

A quantitative CRP test costs about ₹250 to ₹620 at Metropolis, depending on the city. Its listed prices are ₹500 in Hyderabad, ₹450 in Delhi, ₹540 in Pune, ₹590 to ₹620 in Mumbai and ₹250 in Indore. Reports come within a day. Home collection is available.3 The company's own guide gives ₹350 to ₹650 as the usual span across the big metros.3 Standalone local labs often charge less, and a latex slide test is cheaper again, but reports only positive or negative.7

hs-CRP is a different order code and costs more. Book it only if the reason is heart-risk assessment, and measure it when you are clinically well; a raised result obtained during an infection or other acute illness should be repeated after recovery.16 For fever, joint pain or monitoring a known condition, the standard quantitative CRP is the right test and the cheaper one.

How to reduce CRP Copy link

Short answer. You lower CRP by removing what is driving it. Treat the infection, control the arthritis, let the operation heal, and the number follows within days.1 There is no tablet or diet that lowers CRP as a target in itself, and a high CRP is a reading of something else.

For the persistent 3 to 10 mg/L band, the levers with evidence are weight loss, which lowers CRP in proportion to the fat lost; regular physical activity; stopping smoking; and treating gum disease.12 Moderate alcohol intake is associated with a lower baseline in population studies, which is an observation rather than a prescription.1 Statins lower CRP as well as LDL, by 37 percent in JUPITER.17 GLP-1 medicines used for diabetes and weight have been associated with falls in CRP.2 In both cases the fall comes with treating a condition. Neither is a way to fix a number.

When to see a doctor about a CRP result Copy link

See a doctor the same day for any CRP above 100 mg/L with fever. Go to an emergency department if you have difficulty breathing, confusion, fainting, rapidly worsening illness, severe pain or very little urine, whatever the number is.5 For a CRP between 10 and 100 mg/L, urgency depends on your symptoms and the situation, and hardly at all on whether the number is 15 or 80. Fever with worsening illness, breathing difficulty, severe pain, confusion, fainting or reduced urine output warrants prompt assessment. An unexpected rise in someone otherwise well is usually repeated once any passing illness has settled.1 An isolated standard CRP below 10 mg/L without symptoms is not an acute-care matter, although a persistent low-grade elevation can still carry meaning for heart and metabolic risk.

Bring your earlier reports if you have them. The direction of travel across two or three results is more informative than any single number, and it costs nothing to show it.

Questions people ask about the CRP test Copy link

What CRP level counts as normal?

Under 3 mg/L for most healthy adults. In healthy blood donors the median is 0.8 mg/L, 90 percent are under 3 and 99 percent under 10. Labs print either 3 or 10 mg/L as the upper limit, so compare yours with the range on your own report.

What does CRP mean in a blood test?

CRP stands for C-reactive protein, a protein the liver releases within hours of inflammation anywhere in the body. On a blood report it is a single number, usually in mg/L, that tells you how much inflammation is present. It does not say where the inflammation is or what is causing it.

What CRP level indicates infection?

Over 100 mg/L makes infection the most common explanation, and above 350 mg/L about 9 in 10 people in one hospital series had one, though other major inflammation reaches these levels too. Between 10 and 100 mg/L infection is one of several causes. In an assessed chest infection, a CRP below 20 mg/L lowers the likelihood that antibiotics will help, but it does not rule out bacterial infection.

Is a CRP of 6 high?

Slightly above the level most healthy adults run, and inside what many labs print as normal. A 6 mg/L that is the same every year is your baseline; a 6 that was 1 last year is a small change. It is common with excess weight, smoking, a cold, gum disease and pregnancy.

How much CRP is dangerous?

There is no single dangerous number, because the cause matters more than the level. A CRP over 100 mg/L with fever needs a doctor the same day. Difficulty breathing, confusion, fainting, rapidly worsening illness or very low urine output needs emergency care whatever the number.

Does a high CRP mean cancer?

Rarely. Cancer accounted for about 5 percent of adults with a CRP above 100 mg/L in one hospital series, while infection accounted for 55 percent. A persistently raised CRP with weight loss, night sweats or no other explanation is investigated, but the test itself does not point to cancer.

What is a normal hs-CRP level?

Under 1 mg/L is low cardiovascular risk, 1 to 3 mg/L average and over 3 mg/L high on the 2003 AHA and CDC bands, and newer cardiology guidance treats a persistent level of 2 mg/L or more as raised inflammatory risk. The bands apply to a stable baseline, averaged over two readings about two weeks apart, with any result over 10 repeated after a search for infection.

Is fasting required before a CRP test?

No. CRP is not affected by eating and does not vary with the time of day. If a lab asks you to fast, it is usually because other tests such as glucose or a lipid profile are in the same draw.

How long does CRP take to come down?

The protein itself clears with a half-life of about 19 hours, so once the liver stops making it the level can roughly halve each day. In practice production tapers rather than stops, so the fall is usually slower, over days to a couple of weeks. A number that keeps rising on treatment is a reason to review the diagnosis.

References Copy link

  1. Pepys MB, Hirschfield GM. C-reactive protein: a critical update. J Clin Invest. 2003;111(12):1805-1812. doi:10.1172/JCI18921. https://www.jci.org/articles/view/18921
  2. Singh B, Goyal A, Patel BC. C-Reactive Protein: Clinical Relevance and Interpretation. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; updated 3 May 2025. https://www.ncbi.nlm.nih.gov/books/NBK441843/
  3. Metropolis Healthcare. CRP Test (C-Reactive Protein): price, preparation and reporting time, city pages for Hyderabad, Delhi, Pune, Mumbai and Indore. Accessed 16 September 2026. https://www.metropolisindia.com/parameter/hyderabad/c-reactive-protein-test
  4. MedlinePlus Medical Encyclopedia. C-reactive protein. Bethesda (MD): National Library of Medicine. https://medlineplus.gov/ency/article/003356.htm
  5. MedlinePlus Medical Tests. C-Reactive Protein (CRP) Test. Bethesda (MD): National Library of Medicine; last updated 11 June 2025. https://medlineplus.gov/lab-tests/c-reactive-protein-crp-test/
  6. Dr Lal PathLabs. C-Reactive Protein Test: What Is It & What Does the Result Mean? Blog, 25 September 2025. https://www.lalpathlabs.com/blog/c-reactive-protein-test/
  7. Arlington Scientific. ASI CRP Latex Test Kit: sensitivity 6 mg/L, qualitative and semiquantitative slide agglutination. https://www.arlingtonscientific.com/crp
  8. Causes and outcomes of markedly elevated C-reactive protein levels. Can Fam Physician. 2017;63(6):e316-e323. Retrospective, single center. https://pmc.ncbi.nlm.nih.gov/articles/PMC5471098
  9. Van Hecke O, Bjerrum L, Gentile I, Hopstaken R, Melbye H, Plate A, Verbakel JY, Llor C, Staiano A. Guidance on C-reactive protein point-of-care testing and complementary strategies to improve antibiotic prescribing for adults with lower respiratory tract infections in primary care. Front Med. 2023;10:1166742. doi:10.3389/fmed.2023.1166742. Funded by Abbott Rapid Diagnostics. https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2023.1166742/full
  10. Kruidenier J, Dingemans SA, van Dieren S, de Jong VM, Goslings JC, Schepers T. C-reactive protein kinetics and its predictive value in orthopedic (trauma) surgery: A systematic review. Acta Orthop Belg. 2018;84(4). https://actaorthopaedica.be/archive/volume-84/issue-4/original-studies/c-reactive-protein-kinetics-and-its-predictive-value-in-orthopedic-trauma-surgery-a-systematic-revi/
  11. National Institute for Health and Care Excellence. Suspected acute respiratory infection in over 16s: assessment at first presentation and initial management. NICE guideline NG237. London: NICE; 31 October 2023, last updated 2 September 2025, recommendations 1.3, point-of-care CRP thresholds of 20 and 100 mg/L. https://www.nice.org.uk/guidance/ng237
  12. National Institute for Health and Care Excellence. Pneumonia in adults: diagnosis and management. Clinical guideline CG191. London: NICE; 3 December 2014, recommendation 1.1.1 (superseded by NG237 in October 2023). https://www.nice.org.uk/guidance/cg191
  13. Smedemark SA, Aabenhus R, Llor C, Fournaise A, Olsen O, Jørgensen KJ. Biomarkers as point-of-care tests to guide prescription of antibiotics in people with acute respiratory infections in primary care. Cochrane Database Syst Rev. 2022;10:CD010130. doi:10.1002/14651858.CD010130.pub3. https://doi.org/10.1002/14651858.CD010130.pub3
  14. Sangle AL, et al. Role of Point-of-Care C-reactive Protein Testing on Antibiotic Prescription in Febrile Children: A Randomized Controlled Trial. Cureus. 2025;17(9):e92646. doi:10.7759/cureus.92646. Open-label, single center. https://www.cureus.com/articles/400178-role-of-point-of-care-c-reactive-protein-testing-on-antibiotic-prescription-in-febrile-children-a-randomized-controlled-trial
  15. Chambers JC, Eda S, Bassett P, Karim Y, Thompson SG, Gallimore JR, Pepys MB, Kooner JS. C-reactive protein, insulin resistance, central obesity, and coronary heart disease risk in Indian Asians from the United Kingdom compared with European whites. Circulation. 2001;104(2):145-150. doi:10.1161/01.cir.104.2.145. https://pubmed.ncbi.nlm.nih.gov/11447077/
  16. Pearson TA, Mensah GA, Alexander RW, et al. Markers of inflammation and cardiovascular disease: application to clinical and public health practice: a statement for healthcare professionals from the Centers for Disease Control and Prevention and the American Heart Association. Circulation. 2003;107(3):499-511. PMID 12551878. https://pubmed.ncbi.nlm.nih.gov/12551878/
  17. Ridker PM, Danielson E, Fonseca FA, Genest J, Gotto AM Jr, Kastelein JJ, Koenig W, Libby P, Lorenzatti AJ, MacFadyen JG, Nordestgaard BG, Shepherd J, Willerson JT, Glynn RJ; JUPITER Study Group. Rosuvastatin to prevent vascular events in men and women with elevated C-reactive protein. N Engl J Med. 2008;359(21):2195-2207. doi:10.1056/NEJMoa0807646. Funded by AstraZeneca. https://pubmed.ncbi.nlm.nih.gov/18997196/
  18. Mensah GA, Arnold N, Prabhu SD, Ridker PM, Welty FK, et al. Inflammation and Cardiovascular Disease: 2025 ACC Scientific Statement: A Report of the American College of Cardiology. J Am Coll Cardiol. Published online 29 September 2025. doi:10.1016/j.jacc.2025.08.047. https://www.jacc.org/doi/10.1016/j.jacc.2025.08.047
  19. American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. 2026 ACC/AHA/AACVPR/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Dyslipidemia: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Circulation. 2026. doi:10.1161/CIR.0000000000001423. https://www.ahajournals.org/doi/10.1161/CIR.0000000000001423

This article is general health information and does not diagnose anything. Every laboratory sets its own reference interval and reports in its own unit, so the interval and unit printed on your report come first, and a result outside it is a question for a doctor who can examine you. Sapiens is operated by Pangaea Sciences Private Limited, Hyderabad. Editorial standards: joinsapiens.in/editorial-standards. Report an error on this page.