High ESR and CRP Test: What It Means, Normal Range (इएसआर, सीआरपी)
By Dr. Krishna Adhikari, Consultant Rheumatologist
MBBS, MD (Internal Medicine), Fellowship in Clinical Rheumatology
Awaiting medical review: this new article has not yet been checked by Dr. Krishna Adhikari. It will be updated after his review.
A high ESR or CRP can mean there is inflammation somewhere in the body, but neither blood test can show where it is or what is causing it. Infections and autoimmune diseases such as rheumatoid arthritis and lupus can raise both, and the ESR can also rise with anaemia, pregnancy and older age, so a doctor reads the result together with your symptoms, an examination and other tests.
What are ESR and CRP?
ESR (इएसआर), the erythrocyte sedimentation rate or "sed rate", measures how quickly red blood cells (erythrocytes) sink to the bottom of a tall, thin tube of your blood, in millimetres per hour (mm/hr). Inflammation makes red cells stick together in clumps that sink faster, so a faster rate means more inflammation.
CRP (सीआरपी), C-reactive protein, is a protein your liver makes in response to inflammation: the immune system's response to injury, infection and many other conditions. Both tests use a blood sample from a vein in your arm.
Why does a rheumatologist order ESR and CRP?
Rheumatoid arthritis, lupus, vasculitis (inflammation of the blood vessel walls) and many other rheumatic diseases cause inflammation. NIAMS, the US National Institute of Arthritis and Musculoskeletal and Skin Diseases, says the sed rate and CRP help monitor disease activity and response to treatment in rheumatoid arthritis. Lab Tests Online UK notes that the ESR is especially helpful in diagnosing polymyalgia rheumatica (muscle pain and stiffness in the shoulders and hips) and giant cell arteritis (inflammation of arteries, especially at the sides of the head), two linked conditions that NIAMS says almost always occur in people older than 50.
What is the difference between ESR and CRP?
Both show inflammation, and doctors often order them together.
CRP rises within a few hours of an infection, injury or other inflammation, and falls faster as it settles. The ESR changes more slowly and can stay raised after CRP is back to normal.
The ESR is affected by more things besides inflammation, such as anaemia, age, sex and pregnancy.
The high-sensitivity CRP (hs-CRP) test also measures CRP, but it is used for a different purpose: to estimate the risk of heart disease.
What is a normal ESR level?
MedlinePlus, from the US National Library of Medicine, gives these normal ESR values (Westergren method):
Men under 50: less than 15 mm/hr
Men over 50: less than 20 mm/hr
Women under 50: less than 20 mm/hr
Women over 50: less than 30 mm/hr
Newborn babies: 0 to 2 mm/hr; children up to puberty: 3 to 13 mm/hr
Laboratories use their own ranges; read the range printed on your report.
What does a high ESR indicate?
A high ESR means your red blood cells sank faster than normal, which may be caused by a condition that produces inflammation. MedlinePlus lists many possible causes, including:
infections, including tuberculosis
rheumatoid arthritis, lupus, polymyalgia rheumatica and other autoimmune diseases, in which the immune system attacks the body's own tissue by mistake
giant cell arteritis and vasculitis
kidney or thyroid disease
anaemia, when the blood does not carry enough oxygen
certain cancers, such as lymphoma or multiple myeloma
pregnancy
A high ESR does not prove any of these, and MedlinePlus says other tests are almost always needed. Age, sex, periods, obesity, regular alcohol, exercise and some medicines can also affect the result. According to Lab Tests Online UK, a single raised ESR without symptoms usually does not give the doctor enough information to make a decision. A normal ESR does not rule out inflammation either.
Is an ESR of 35 or 40 high?
Yes: 35 and 40 mm/hr are both above the normal values MedlinePlus lists for adult men and women. It is a result to discuss with a doctor, not a diagnosis: Lab Tests Online UK notes that a moderately raised ESR occurs with inflammation, but also with anaemia, pregnancy and old age.
What happens if my ESR is 70 or higher?
That is well above every adult value listed by MedlinePlus, so show the report to a doctor soon. Lab Tests Online UK says a very high ESR usually has an obvious cause, such as an infection, and MedlinePlus also links very high levels with giant cell arteritis and some types of vasculitis. Follow-up tests look for the cause.
Is ESR related to the kidneys?
Kidney disease can raise the ESR. But the ESR cannot show which part of the body is affected, so a high result alone does not mean your kidneys have a problem.
What is a normal CRP level?
MedlinePlus says healthy people have very low amounts of CRP: 0.8 to 1.0 milligrams per decilitre (mg/dL) or lower is thought to be healthy, and most healthy adults have less than 0.3 mg/dL. Some laboratories report CRP in milligrams per litre (mg/L): 1 mg/dL equals 10 mg/L, so 0.3 mg/dL is 3 mg/L and 1.0 mg/dL is 10 mg/L. Laboratories use their own ranges; read the range printed on your report.
What does a CRP test mean?
A CRP test tells your doctor how much inflammation there is in your body, but, as MedlinePlus puts it, not what is causing it or where it is. MedlinePlus lists these causes of a high CRP:
infections caused by bacteria or viruses
autoimmune diseases, such as lupus, rheumatoid arthritis and vasculitis
inflammatory bowel disease and lung diseases such as asthma
smoking and polluted air
Cleveland Clinic lists obesity, a common cold, gum disease, a recent injury and pregnancy among the causes of smaller rises. The MedlinePlus Medical Encyclopedia calls 1 to 10 mg/dL (10 to 100 mg/L) a moderate increase, and above 10 mg/dL (above 100 mg/L) a marked increase. It also notes that CRP may not rise in people with rheumatoid arthritis and lupus, so a normal CRP does not always rule out inflammation.
When should I worry about a high CRP?
A slightly high CRP does not necessarily mean you need treatment; Cleveland Clinic notes that about 1 in 20 healthy people have results outside the normal range. Get medical help urgently if you feel very unwell with fever or chills, a fast heartbeat or fast breathing. MedlinePlus lists these as symptoms of a bacterial infection, and an infection that spreads to the blood (sepsis) is a life-threatening emergency.
Does a positive CRP mean fever?
No. A positive CRP means there is inflammation in the body; it does not measure fever. Infections can raise it, often before pain or fever appear, but so can autoimmune diseases such as rheumatoid arthritis and lupus.
Do I need to fast before an ESR or CRP test?
No. MedlinePlus and Lab Tests Online UK say neither test needs special preparation, and Cleveland Clinic says you can eat and drink as usual before an ESR test. You may need to fast if your doctor has ordered other tests on the same blood sample. Tell the doctor about every medicine and supplement you take, as some change the result, but do not stop a prescribed medicine on your own. Your doctor will tell you which tests you need; ask the laboratory for its current price and any preparation.
What happens after a high ESR or CRP result?
Your doctor reads the result together with your medical history, symptoms and an examination, and may repeat the test after some weeks or order other tests chosen according to your symptoms, such as a full blood count, ANA or rheumatoid factor. Treatment is aimed at the cause, and Lab Tests Online UK notes that the ESR usually comes down once the inflammation is treated. In a known condition such as rheumatoid arthritis, a rising result can mean more inflammation and a falling one a good response to treatment, so bring your old reports to each visit.
Other blood tests a rheumatologist may order
Other tests help show which disease may be causing the inflammation:
Rheumatoid factor (RF) and anti-CCP for rheumatoid arthritis. NIAMS notes that some people with a positive RF never develop the disease, and some people with rheumatoid arthritis have normal blood tests.
ANA (antinuclear antibodies) for lupus. According to NIAMS, almost all people with lupus have a positive ANA, but so can healthy people.
HLA-B27, a gene found in most people with ankylosing spondylitis; you can have the gene and never develop the disease.
Uric acid for gout. The American College of Rheumatology notes that high levels do not always mean gout.
इएसआर (ESR) र सीआरपी (CRP): नेपालीमा संक्षेप
इएसआर (ESR) र सीआरपी (CRP) शरीरभित्र सुजन (इन्फ्लामेसन) छ कि छैन भनेर हेर्ने रगत जाँच हुन्। सीआरपी भनेको सुजन हुँदा कलेजोले बनाउने प्रोटिन हो। यी जाँच बढी आउनुको अर्थ शरीरमा कतै सुजन हुन सक्छ भन्ने हो, तर कुन रोग हो वा कहाँ छ भन्ने यसले बताउँदैन। संक्रमण र रुमाटोइड आर्थराइटिस (गठिया बाथ) तथा लुपसजस्ता अटोइम्युन रोगले दुवै बढाउन सक्छन्। रक्तअल्पता (रगतको कमी), गर्भावस्था र बढ्दो उमेरले पनि इएसआर बढाउन सक्छ।
मेडलाइनप्लस (MedlinePlus) का अनुसार वयस्कमा इएसआरको सामान्य मान ५० वर्षमुनिका पुरुषमा १५ mm/hr भन्दा कम, ५० वर्षमाथिका पुरुषमा २० भन्दा कम, ५० वर्षमुनिका महिलामा २० भन्दा कम र ५० वर्षमाथिका महिलामा ३० भन्दा कम हो। स्वस्थ व्यक्तिमा सीआरपी धेरै कम हुन्छ। प्रयोगशालाअनुसार दायरा फरक हुन्छ, त्यसैले आफ्नो रिपोर्टमा छापिएको दायरा हेर्नुहोस्।
यी जाँचका लागि खाली पेट बस्नु पर्दैन; सँगै अरू जाँच पनि गर्नु छ भने डाक्टरको निर्देशन मान्नुहोस्। आफूले खाने सबै औषधिबारे डाक्टरलाई भन्नुहोस्। ज्वरो आउने वा काम्ने, मुटु छिटो धड्किने वा छिटो सास फेर्ने भई धेरै बिरामी महसुस भए तुरुन्तै उपचार लिनुहोस्। ५० वर्षमाथिका व्यक्तिमा नयाँ टाउको दुखाइ वा बङ्गारा दुखाइ भए ढिला नगरी डाक्टरलाई देखाउनुहोस्, र आँखाले देख्न गाह्रो भए तुरुन्तै उपचार लिनुहोस्। डाक्टरले तपाईंका लक्षण, जाँच र अरू रिपोर्टसँगै नतिजा हेरेर कारण खोज्नुहुन्छ।
When to see a rheumatologist
See a doctor if a raised ESR or CRP comes with joint pain, swelling or stiffness that has not settled, neck or shoulder pain, unexplained fever or weight loss. If you are over 50 and have a new headache, scalp tenderness or jaw pain, see a doctor urgently: NIAMS lists these as common features of giant cell arteritis, which the NHS says is serious and needs urgent treatment. Seek treatment right away if your vision changes, because NIAMS warns that untreated visual symptoms can lead to blindness.
Rheumatology care in Kathmandu Valley
Rheumatology care at Tulsi Multi Speciality Clinic is provided by Dr. Krishna Adhikari, consultant rheumatologist and Lecturer in Internal Medicine at Patan Academy of Health Sciences (Patan Hospital), NMC No. 13049. He consults Sunday to Friday from 4:00 PM at AVM Chowk, Manbhawan, Lalitpur-5, Kathmandu Valley. See our rheumatology service and Dr. Krishna Adhikari's profile, book an appointment, or call +977-1-5914294. This article is general information, not a substitute for a consultation.
Sources
Rheumatology care at Tulsi Multi Speciality Clinic · Dr. Krishna Adhikari, consultant rheumatologist
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