The C-Reactive Protein blood test measures CRP, a non-specific marker that can increase when inflammation is present in the body. It may support the investigation or monitoring of infection, inflammatory conditions and treatment response.
C-Reactive Protein, commonly known as CRP, is a protein produced mainly by the liver as part of the body’s response to inflammation.
The amount of CRP in the blood may increase when the immune system responds to infection, inflammatory disease, tissue injury, trauma or surgery.
CRP levels can change relatively quickly. For this reason, the test may be used to support the assessment of current inflammation and to monitor changes over time.
A CRP result may help:
• Identify evidence of an inflammatory response
• Support the investigation of possible infection or inflammation
• Assess the degree of an inflammatory response
• Monitor a known inflammatory condition
• Monitor changes during illness or treatment
• Support follow-up after surgery, injury or treatment when clinically appropriate
CRP is a non-specific marker. It cannot identify the exact cause or location of inflammation and cannot provide a diagnosis on its own.
This test measures the concentration of C-Reactive Protein in a venous blood sample.
The laboratory normally reports the result in milligrams per litre, written as mg/L.
CRP may increase when inflammatory activity is present in the body.
An increased result may occur in association with:
• Bacterial or viral infections
• Inflammatory or autoimmune conditions
• Tissue injury or trauma
• Recent surgery
• Some chronic medical conditions
• Other causes of inflammation
The test cannot identify which organ or part of the body is affected.
When CRP is used for monitoring, the pattern across several results may be more informative than one result.
A rising CRP concentration may indicate increasing inflammatory activity. A falling result may be consistent with improvement or response to treatment.
However, CRP results must always be considered alongside symptoms, medical history, examination findings and other investigations.
The following tests, services and investigations are not included in this individual CRP blood test:
• High-Sensitivity C-Reactive Protein (hs-CRP)
• Cardiovascular-risk assessment
• Erythrocyte Sedimentation Rate (ESR)
• Full Blood Count (FBC)
• Blood cultures
• Infection-specific testing
• Autoimmune antibody testing
• Rheumatoid factor
• Anti-CCP antibodies
• Antinuclear antibody testing
• Liver or kidney function testing
• Medical consultation or physical examination
• Identification of the cause or location of inflammation
• Medical diagnosis or treatment
IMPORTANT: Standard CRP and high-sensitivity CRP are different tests.
The standard CRP test on this page is used to assess general inflammatory activity. It is not the high-sensitivity CRP test sometimes used as part of cardiovascular-risk assessment.
If you require hs-CRP, ESR, FBC or another investigation, it must be ordered separately.
You may consider a CRP blood test if you:
• Have been advised to arrange the test by a healthcare professional
• Have symptoms that may be associated with inflammation
• Are being assessed for a possible infection or inflammatory condition
• Have a known inflammatory or autoimmune condition requiring monitoring
• Need to monitor changes in inflammation over time
• Need to monitor response to treatment under professional guidance
• Require follow-up after illness, injury or surgery when recommended
• Have a previous elevated CRP result that requires follow-up
Possible symptoms of infection or inflammation may include:
• Fever or chills
• Persistent fatigue or feeling generally unwell
• Muscle or joint pain
• Swelling or stiffness
• Localised redness, warmth or tenderness
• Persistent symptoms following an illness
These symptoms may have many possible causes. A CRP test cannot identify the cause or provide a diagnosis on its own.
CRP is not generally recommended as a standalone screening test for someone who is well and has no symptoms or clinical reason for testing.
Test name: C-Reactive Protein
Also known as: CRP or standard CRP
Test category: Clinical Biochemistry
Laboratory test code: CRP
Sample required: Venous blood sample
Laboratory sample type: Serum
Collection tube: Gold-top serum tube
Fasting required: No
Special preparation: No special preparation is normally required
Appointment duration: Approximately 15 minutes
Minimum age: Adults aged 18 and over
Estimated turnaround time: Usually within 1 working day after the sample reaches the laboratory
Laboratory testing: Testing is performed by an accredited partner laboratory
Available collection methods:
• Clinic Blood Collection
• Home Visit Blood Collection
Turnaround times are estimates and are not guaranteed. Results may take longer if the laboratory needs to repeat the analysis, perform additional checks or request a replacement sample.
Fasting is not required for this test. You may eat and drink normally before your appointment.
Before your appointment:
• Drink water and remain normally hydrated unless a healthcare professional has restricted your fluid intake.
• Continue taking prescribed medication unless the clinician responsible for your care has instructed you otherwise.
• Do not stop or change prescribed medication based on information from this website.
• Tell us about any current symptoms, recent infection or ongoing illness.
• Tell us if you have recently had surgery, an injury, trauma or a vaccination.
• Tell us if you have a diagnosed inflammatory or autoimmune condition.
• Provide details of previous CRP results if the test is being used for monitoring.
• Tell us about medication that may affect inflammation, including corticosteroids, anti-inflammatory medicines or immune-suppressing treatment.
• Tell the phlebotomist if you have previously fainted or felt unwell during a blood test.
Strenuous exercise, recent injury, surgery, infection and other inflammatory events may affect the result. If the test is being used for monitoring, discuss the timing with the healthcare professional responsible for your care.
Add the C-Reactive Protein blood test to your shopping cart.
Add either Clinic Blood Collection or Home Visit Blood Collection to your cart.
Please select one collection method only. Do not add both options.
Select “Book Your Appointment” and choose an available date and time for your blood sample collection.
Please use the same name, telephone number and email address used when placing your order.
Your identity and order will be checked before your blood sample is collected.
Your sample will be transported to our accredited partner laboratory for analysis.
Your laboratory report will be delivered securely when the testing process is complete.
BUTTON: Book Your Appointment
Your laboratory report will show your CRP concentration together with the reporting laboratory’s reference range.
Reference ranges and interpretation may vary according to the laboratory and analytical method used.
A result within the laboratory reference range means that a significant systemic inflammatory response was not identified at the time your sample was collected.
However, a normal CRP result does not exclude:
• Early infection
• Localised infection
• All inflammatory conditions
• Autoimmune disease
• Other causes of your symptoms
If your symptoms continue or worsen, seek advice from your GP or another qualified healthcare professional.
An increased CRP result suggests that an inflammatory response may be present.
Possible reasons include:
• Infection
• Inflammatory or autoimmune disease
• Recent surgery
• Injury or trauma
• Tissue damage
• Some chronic health conditions
• Other causes of inflammation
The result does not identify the cause or location of the inflammation.
A CRP result alone cannot reliably determine whether an infection is bacterial or viral and cannot determine whether antibiotics are required.
When CRP is used for monitoring, repeat results may help show whether inflammatory activity is increasing or decreasing.
Results should be considered alongside:
• Your symptoms
• Medical history
• Clinical examination
• Medication and treatment
• Previous CRP measurements
• Other blood tests
• Imaging or microbiology results, where appropriate
Please discuss an increased or unexpected result with your GP or another qualified healthcare professional.
A CRP test is not a substitute for clinical assessment and must not be used to delay urgent medical care.
Alpha Med Lab does not provide emergency infection assessment, diagnosis or treatment.
Call NHS 111 urgently if you:
• Feel very unwell or believe something is seriously wrong
• Have a very high or very low temperature
• Have uncontrollable shivering
• Have worsening pain or swelling around a wound
• Have not passed urine all day or are passing much less urine than normal
• Have persistent symptoms of infection that are getting worse
Call 999 or attend Accident & Emergency immediately if you or someone else:
• Is confused, has slurred speech or is not making sense
• Has severe difficulty breathing or is breathing very quickly
• Has blue, grey, pale or blotchy skin, lips or tongue
• Has a rash that does not fade when pressed
• Collapses, faints or is difficult to wake
• Has severe or rapidly worsening symptoms
These may be signs of a serious infection or sepsis.
Do not wait for a CRP appointment or laboratory result if you are seriously unwell.
If you are uncertain whether the C-Reactive Protein test is suitable for you, please contact Alpha Med Lab before placing your order.
Telephone: 07448 342115
Email: info@alphamedlab.co.uk
If you feel seriously unwell or have symptoms of a severe infection, seek urgent medical care instead of booking a routine private blood test.
Add the £100 C-Reactive Protein blood test to your cart, select one blood collection method and then book your appointment.
IMPORTANT: Blood collection is charged separately.
