HsCRP (High-Sensitivity CRP) Blood Test: Normal Ranges, Causes & What Your Results Mean

What Is HsCRP (High-Sensitivity CRP)?

High-sensitivity C-reactive protein (hsCRP) is a blood marker that measures very low levels of C-reactive protein, a substance produced by the liver in response to inflammation anywhere in the body. While standard CRP tests detect the large elevations in CRP that accompany acute infections or severe inflammatory conditions, the high-sensitivity version is designed to detect the much subtler, chronic low-grade inflammation that plays a critical role in cardiovascular disease.

CRP is an acute-phase protein — part of the body's innate immune response. When tissue damage or infection occurs, inflammatory signals (particularly interleukin-6) stimulate the liver to produce CRP, which then activates the complement system and promotes phagocytosis to help fight infection and clear damaged cells.

The clinical importance of hsCRP lies in its ability to detect the low-level, persistent inflammation associated with atherosclerosis — the build-up of fatty plaques in the arteries that leads to heart attacks and strokes. Research over the past two decades has consistently shown that hsCRP is an independent predictor of cardiovascular events, even in individuals with normal cholesterol levels. The American Heart Association and the European Society of Cardiology recognise hsCRP as a valuable tool for cardiovascular risk assessment.

In the UK, hsCRP is increasingly used alongside traditional risk factors (blood pressure, cholesterol, smoking status, diabetes, family history) to provide a more complete picture of cardiovascular risk.

Why Is HsCRP Tested?

HsCRP testing serves several important clinical purposes:

• Cardiovascular risk assessment: HsCRP adds predictive value beyond traditional risk factors. It is particularly useful for individuals at intermediate cardiovascular risk, where the result may influence decisions about statin therapy or lifestyle intervention intensity.
• Metabolic syndrome evaluation: Chronic low-grade inflammation is a hallmark of metabolic syndrome, insulin resistance, and type 2 diabetes. HsCRP is often elevated in these conditions and correlates with abdominal obesity.
• Monitoring inflammatory conditions: While hsCRP is primarily used for cardiovascular risk, it can also track the level of systemic inflammation in conditions such as rheumatoid arthritis, inflammatory bowel disease, and lupus.
• Post-cardiac event monitoring: After a heart attack or stroke, hsCRP levels help assess residual inflammatory risk and guide decisions about anti-inflammatory treatment strategies.
• Research and clinical trials: HsCRP is widely used as an endpoint in cardiovascular and anti-inflammatory treatment trials. The landmark JUPITER trial demonstrated that statin therapy benefits individuals with elevated hsCRP even when LDL cholesterol is normal.
• General health screening: As part of a comprehensive blood panel, hsCRP provides insight into your body's overall inflammatory status, which is linked to numerous chronic diseases beyond cardiovascular disease.

Normal Ranges

HsCRP is measured in milligrams per litre (mg/L). The following classification is widely used for cardiovascular risk stratification:

HsCRP Level (mg/L)	Cardiovascular Risk Category	Interpretation
< 1.0	Low risk	Low level of systemic inflammation; lower cardiovascular risk
1.0 – 3.0	Average risk	Moderate inflammation; average cardiovascular risk
> 3.0	High risk	Elevated inflammation; higher cardiovascular risk
> 10.0	Acute inflammation	Likely reflects acute infection or inflammatory condition rather than cardiovascular risk; repeat after resolution

Important considerations when interpreting hsCRP:

• Values above 10 mg/L usually indicate an acute process (infection, injury, flare of an inflammatory condition) and should not be used for cardiovascular risk assessment. Repeat testing 2-3 weeks later is recommended.
• Two measurements taken 2 weeks apart are recommended for accurate risk stratification, as CRP can fluctuate day to day.
• Women tend to have slightly higher hsCRP levels than men, and levels increase with age and BMI.
• Oral contraceptives and hormone replacement therapy can elevate hsCRP.
• Strenuous exercise can cause temporary elevations.

What Do High HsCRP Levels Mean?

An elevated hsCRP reflects increased systemic inflammation. The causes and associations include:

• Cardiovascular disease risk: Chronic low-grade inflammation drives atherosclerosis. An hsCRP above 3.0 mg/L is associated with approximately twice the cardiovascular risk compared with levels below 1.0 mg/L, independent of cholesterol levels.
• Obesity: Adipose tissue, particularly visceral fat, is metabolically active and produces inflammatory cytokines (adipokines) that stimulate CRP production. Weight loss consistently reduces hsCRP.
• Type 2 diabetes and insulin resistance: Chronic inflammation is both a cause and consequence of insulin resistance. HsCRP is frequently elevated in people with metabolic syndrome and pre-diabetes.
• Smoking: Cigarette smoking causes chronic vascular inflammation and reliably elevates hsCRP. Levels decline after smoking cessation.
• Chronic infections: Persistent bacterial, viral, or parasitic infections (including periodontitis — gum disease) can maintain elevated CRP levels.
• Autoimmune conditions: Rheumatoid arthritis, lupus, inflammatory bowel disease, and psoriasis are characterised by chronic inflammation and elevated hsCRP.
• Sleep deprivation: Poor sleep quality and insufficient sleep duration are associated with elevated inflammatory markers, including hsCRP.
• Depression: A growing body of evidence links major depressive disorder with systemic inflammation, and hsCRP levels are often elevated in people with depression.

What Do Low HsCRP Levels Mean?

A low hsCRP (below 1.0 mg/L) is a favourable finding that generally indicates:

• Low cardiovascular risk: A level below 1.0 mg/L places you in the lowest cardiovascular risk category based on inflammation. Combined with healthy cholesterol levels and blood pressure, this is highly reassuring.
• Good metabolic health: Low hsCRP is associated with healthy insulin sensitivity, normal body weight, and absence of metabolic syndrome.
• Healthy lifestyle: Regular physical activity, a balanced diet, non-smoking status, and healthy sleep patterns all contribute to low systemic inflammation.
• Effective treatment: In patients taking statins or anti-inflammatory medications, declining hsCRP indicates a good therapeutic response. The JUPITER trial showed that achieving hsCRP below 2.0 mg/L on statin therapy was associated with significantly better cardiovascular outcomes.
• Absence of significant chronic disease: Low hsCRP suggests that chronic inflammatory conditions, active infections, and autoimmune flares are unlikely.
• Genetic factors: Some individuals naturally have lower baseline CRP levels due to genetic variation in the CRP gene and related inflammatory pathways.

How to Improve Your HsCRP Levels

Reducing hsCRP focuses on addressing the root causes of chronic inflammation through lifestyle modification and, when appropriate, medical treatment:

Diet

• Adopt a Mediterranean-style diet: Rich in olive oil, fruits, vegetables, whole grains, fish, nuts, and legumes, the Mediterranean diet has been consistently shown to reduce hsCRP and cardiovascular risk. The PREDIMED trial demonstrated a 30% reduction in cardiovascular events.
• Increase omega-3 fatty acids: Oily fish (salmon, mackerel, sardines), walnuts, and flaxseeds contain omega-3 fatty acids that have anti-inflammatory properties. Aim for at least two portions of oily fish per week, as recommended by the NHS.
• Reduce processed foods and sugar: Ultra-processed foods, refined carbohydrates, and added sugars promote inflammation. Minimising these is one of the most effective dietary changes you can make.
• Eat more fibre: A high-fibre diet (30g per day, as recommended by the NHS) is associated with lower hsCRP levels. Whole grains, vegetables, legumes, and fruits are excellent sources.

Exercise

• Regular moderate exercise: The NHS recommends 150 minutes of moderate-intensity activity per week. Regular exercise has a powerful anti-inflammatory effect, reducing hsCRP by 20-30% in most studies, independent of weight loss.
• Combine aerobic and resistance training: Both types of exercise independently reduce inflammation. A combination provides the greatest benefit.

Weight Management

• Lose excess weight: Even a 5-10% reduction in body weight can significantly lower hsCRP. Visceral fat loss is particularly effective at reducing inflammation.

Lifestyle Factors

• Stop smoking: Smoking cessation reduces hsCRP within weeks. The NHS offers free stop smoking support services.
• Improve sleep: Aim for 7-9 hours of quality sleep per night. Treat underlying sleep disorders such as obstructive sleep apnoea, which is strongly associated with elevated hsCRP.
• Manage stress: Chronic psychological stress elevates inflammatory markers. Mindfulness-based stress reduction, meditation, yoga, and cognitive behavioural therapy have all been shown to reduce hsCRP.
• Address dental health: Periodontitis (gum disease) is a common and often overlooked source of chronic inflammation. Regular dental check-ups and good oral hygiene can help lower systemic inflammation.

When Should You Get Tested?

HsCRP testing is valuable in the following situations:

• You want a comprehensive assessment of your cardiovascular risk
• You have intermediate cardiovascular risk and the result would influence treatment decisions
• You have metabolic syndrome, insulin resistance, or type 2 diabetes
• You have a family history of heart disease or stroke
• You are overweight or obese and want to monitor the inflammatory impact
• You are monitoring the effectiveness of lifestyle changes or medication on inflammation
• You have an autoimmune or inflammatory condition and want to track disease activity
• You are interested in a broad health assessment including inflammatory markers

For cardiovascular risk assessment, hsCRP is best measured when you are free from acute illness, injury, or infection, as these will temporarily elevate the reading. If your first result is above 10 mg/L, wait until the acute process resolves and retest.

Which Lola Health Tests Include HsCRP?

HsCRP is included in several Lola Health blood panels, reflecting its importance as a key indicator of cardiovascular and inflammatory health:

• Peak Insights — Our most comprehensive health panel, including hsCRP alongside a full cardiovascular risk profile, metabolic markers, and much more.
• Vital Check — A detailed wellness assessment that includes hsCRP and other key inflammatory and cardiovascular markers.
• Core Health — Our essential health check covering foundational biomarkers including inflammatory markers to give you a clear picture of your health.

All Lola Health tests use venous blood draws performed by qualified phlebotomists for medical-grade accuracy. Results are reviewed by GP-certified professionals and delivered with personalised health recommendations.