Rheumatoid arthritis Factor (RA Factor / RF / RFAC / RhF)

Clinical definition of the Rheumatoid factor test
Rheumatoid factor is an autoantibody most often associated with autoimmune diseases; mostly Rheumatoid arthritis which attacks synovial joints and Sjögren's syndrome that affects the glands that produce tears & saliva.

Why is the Rheumatoid factor test done?
Rheumatoid factor is one of a group of blood tests, commonly used for the diagnosis, screening and the progress of the autoimmune diseases such as rheumatoid arthritis.

What are the common signs/symptoms when the Rheumatoid factor test is done?
The disease often begins slowly, with symptoms that are seen in many other illnesses:

  • Fatigue
  • Joint pain
  • Weakness
  • Dry eyes
  • Dry mouth
  • Loss of appetite
  • Low fever
  • Swollen glands
  • Chest pain when taking a breath
  • Eye burning
  • Itching
  • Discharge
  • Nodules under the skin
  • Numbness, tingling, or burning in the hands and feet
  • Joint pain in the mornings especially
  • Warm, tender, and stiff joints  when not used
  • Joint pain is on both sides of the body
  • Swollen and spongy joints
  • Joints may become deformed over the time
  • Joint destruction may occur within 1 - 2 years after the disease appears

Who should do the Rheumatoid factor test (Target population)?
Persons showing the above signs & symptoms must get tested for Rheumatoid Factor.

What should I do before the Rheumatoid factor test?

Specimen type

Specimen collection procedure

Preparatory instructions before the test *


(Blood Sample)


(Collection of blood from a vein, usually from the arm)

No Fasting Required.

No other special preparations required.

*Subjects suffering from any illness or on oral or injectable medications are advised to consult their physician prior to requesting any tests or procedures.

How do I interpret my Rheumatoid factor test results?

Reference Range*


Below 15 IU/ml


Inference: The higher the level of RF, the greater the probability of destructive autoimmune disease. 

‘*A Reference range is a set of values which helps the healthcare professional to interpret a medical test. It may vary with age, gender, and other factors. Reference ranges may also vary between labs, in value & units depending on instruments used and method of establishment of reference ranges’

Diseases/conditions related to the Rheumatoid factor test
A higher level of rheumatoid factor in your blood is closely associated with autoimmune disease, particularly rheumatoid arthritis. However, a number of other diseases and conditions can raise rheumatoid factor levels, including:

  • Sjögren's syndrome 
  • Epstein-barr virus infection
  • Parvovirus infection.
  • Chronic hepatitis
  • Primary biliary cirrhosis
  • Any chronic viral infection
  • Bacterial endocarditis
  • Leukemia
  • Dermatomyositis
  • Infectious mononucleosis
  • Systemic sclerosis 
  • Systemic lupus erythematosus (SLE)
  • Cancer
  • Cryoglobulinemia
  • Mixed connective tissue disease
  • Scleroderma

Other tests related to the Rheumatoid factor test

  • Antinuclear antibody (ANA)
  • Haemogram
  • C-reactive protein (CRP)
  • Erythrocyte sedimentation rate (ESR)
  • Anti-CCP
  • Autoantibodies
  • CCP (Cyclic Citrullinated Peptide Antibody)  
  • ENA panel
  • Synovial Fluid Analysis
  • Joint ultrasound or MRI
  • Joint X-rays

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RA Factor (Serum)