C-reactive protein (CRP) is a substance made by the liver and released into the blood in response to inflammation. It serves as a general marker indicating that the body is reacting to some form of stress or infection. Healthcare professionals often rely on this measurement to track or identify underlying inflammatory disorders like infections or autoimmune diseases such as arthritis. The test is frequently requested when an inflammatory condition is suspected or needs ongoing assessment during treatment.
What Does CRP Do?
CRP is synthesized in the liver whenever the body senses inflammation. This inflammation might be the result of an infection, chemical exposure, or physical injury. When the immune system identifies a threat—whether it be a pathogen like bacteria or a traumatic injury—it mobilizes its defense mechanism. This response includes the activation of inflammatory molecules and immune cells aimed at repairing tissue or eliminating the intruder. Externally, this can show up as swelling, redness, or pain, but inflammation also silently impacts areas like joints and organs.
Under healthy circumstances, CRP remains at a low baseline in the bloodstream. A spike in CRP levels usually signals a more serious underlying condition. Elevated CRP can stem from infections, cancer, or even arterial inflammation that may increase cardiovascular risk. Despite its usefulness, CRP testing is non-specific; it can be raised by many different conditions, making additional tests necessary for a full diagnosis.
What Should CRP Levels Be?
CRP levels offer a snapshot of inflammatory activity in the body. While there’s no universally fixed “normal” value, readings under 1 mg/L are typically considered low-risk. If results exceed this threshold—particularly if they remain elevated over time—it may be an indicator of increased risk for cardiovascular issues.
What is High CRP?
When interpreting a high CRP result, healthcare providers consider how much the value surpasses the norm. The degree of elevation can hint at its cause:
- Mild Increase (3–10 mg/L): Often linked to less severe conditions such as obesity, pregnancy, type 2 diabetes, gum disease, or mild viral infections like the common cold.
- Moderate Elevation (Over 10 mg/L): This level may suggest autoimmune disorders like lupus or rheumatoid arthritis, respiratory infections such as bronchitis, pancreatitis, heart-related events like myocardial infarction, or even certain cancers (e.g., breast, colon, lung).
- Marked Increase (Above 100 mg/L): Severe infections or extensive inflammatory processes—such as vasculitis or serious trauma—can cause these elevated levels.
- Extremely High (Over 500 mg/L): This is commonly observed in systemic bacterial infections like sepsis and requires immediate medical intervention.
Your physician will take the test type, clinical history, and possible causes into account when evaluating CRP levels. Particularly high results may prompt more aggressive diagnostic or treatment approaches.
Symptoms of Elevated CRP
While CRP itself doesn’t cause symptoms, its heightened presence usually corresponds to physical signs that indicate systemic inflammation or infection. Common associated symptoms include:
- Persistent fatigue and low energy levels
- Fever and chills, signaling potential infection
- Joint and muscle discomfort, particularly in autoimmune conditions
- Loss of appetite and unexplained weight loss
- Cognitive effects like frequent headaches or difficulty focusing
Causes of Elevated CRP
Numerous conditions can provoke a CRP spike, typically because of an ongoing inflammatory process. Identifying the root cause is essential for effective treatment. Common contributors include:
- Infections: Bacterial infections—especially widespread or serious ones like sepsis—often cause a dramatic increase in CRP. The immune system reacts to the invading pathogens with an inflammatory cascade, raising CRP levels significantly.
- Chronic Inflammatory Conditions: Disorders such as rheumatoid arthritis, Crohn’s disease, or lupus maintain a constant state of inflammation in the body. This chronic immune activation results in persistently elevated CRP levels.
- Cardiovascular Disorders: Arterial inflammation from atherosclerosis can elevate CRP and is considered a warning sign for heart disease and stroke. Monitoring CRP is often advised for patients at risk.
- Surgical Recovery and Trauma: Surgical procedures and major injuries naturally trigger inflammation as part of healing, which may cause a temporary rise in CRP. If levels don’t normalize post-surgery, it might suggest an infection or complication.
- Cancer: Certain cancers, especially those like lymphoma or metastasized tumors, can stimulate inflammation, prompting higher CRP production. It is also possible for CRP levels to rise as the malignancy progresses.
- Autoimmune Conditions: Diseases in which the immune system mistakenly attacks healthy cells—like multiple sclerosis, lupus, or Sjögren’s syndrome—frequently lead to chronic inflammation and elevated CRP levels.
How to Reduce CRP
Several modifiable lifestyle and health factors contribute to high CRP levels. Managing these can help reduce CRP and potentially lower inflammation overall. Steps to take include:
- Achieving and maintaining a healthy weight
- Engaging in regular physical activity
- Managing cholesterol levels effectively
- Keeping blood pressure within a healthy range
- Ensuring good control over blood sugar levels
Although lowering CRP doesn’t directly guarantee a reduced risk of cardiovascular or other diseases, it generally reflects a positive shift in overall health.
What is CRP Turbidimetric Test?
The CRP turbidimetric assay is a laboratory technique used to quantify CRP concentrations in the blood. It is especially favored for its precision and reliability in detecting subtle inflammatory changes. This method is commonly used when high sensitivity is required, making it a valuable tool in both acute and chronic clinical evaluations.