BoneSmart® Hip / Knee Replacement Forum
Knee Replacement & Hip Replacement
Patient Advocacy & Online Community
  1. ATTENTION: Download the new BoneSmart® app today! This FREE app is available for iOS or android phones and tablets and will allow you to connect to the forum on all of your devices. The old Tapatalk app will be discontinued February 1, 2018 so get the new app now.

    Get The app HERE

    Dismiss Notice

CRP and ESR Blood Tests

Discussion in 'LIBRARY General Topics' started by Josephine, Jul 31, 2017.

  1. Josephine

    Josephine FORUM ADMIN, DIRECTOR Administrator
    Thread Starter

    Member Since:
    Jun 8, 2007
    The North
    United Kingdom United Kingdom
    A C-reactive protein (CRP) test is a blood test that measures the amount of a protein called C-reactive protein in your blood. C-reactive protein measures general levels of inflammation in your body. High levels of CRP are caused by infections and many long-term diseases. But a CRP test cannot show where the inflammation is located or what is causing it. Other tests are needed to find the cause and location of the inflammation.


    Normally there is no CRP in blood serum. A high or increasing amount of CRP in the blood suggests that an acute infection or inflammation is present. Although a result above 1 mg/dL is usually considered high for CRP, most infections and inflammations result in CRP levels above 10 mg/dL. [dL = decilitre]

    Reasons for doing a CRP
    A C-reactive protein (CRP) test is done to:
    Check for infection after surgery. CRP levels normally rise within 2 to 6 hours of surgery and then go down by the third day after surgery. If CRP levels stay elevated 3 days after surgery, an infection may be present.​
    Identify and keep track of infections and diseases that cause inflammation, such as:
    Cancer of the lymph nodes (lymphoma).
    Diseases of the immune system, such as lupus.
    Painful swelling of the blood vessels in the head and neck (giant cell arteritis).
    Painful swelling of the tissues that line the joints (rheumatoid arthritis).
    Swelling and bleeding of the intestines (inflammatory bowel disease).
    Infection of a bone (osteomyelitis). (Late onset infection in joint replacements is also osteomyelitis).​

    The ESR and CRP level are raised in many inflammatory conditions. For example:
    Certain infections (mainly bacterial infections)
    Certain types of arthritis
    Various other muscular and connective tissue disorders
    Tissue injury and burns
    Crohn's disease
    Rejection of an organ transplant
    Heart attack​

    ESR or erythrocyte sedimentation rate
    A blood sample is taken and put in a tube that contains a chemical to stop the blood from clotting. The tube is left to stand upright. The red blood cells (erythrocytes) gradually fall to the bottom of the tube (as a 'sediment'). The clear liquid plasma is left at the top. The ESR measures the rate at which the red blood cells separate from the plasma and fall to the bottom of a test tube. The rate is measured in millimetres per hour (mm/hr). This is easy to measure as there will be a number of millimetres of clear liquid at the top of the red blood after one hour.


    Adults (Westergren method):

    Men under 50 years old: less than 15 mm/hr
    Men over 50 years old: less than 20 mm/hr
    Women under 50 years old: less than 20 mm/hr
    Women over 50 years old: less than 30 mm/hr
    • Like Like x 8

Share This Page

Close X