A RA test, more accurately referring to tests for Rheumatoid Arthritis (RA), is a series of blood tests used to identify signs of inflammation and specific antibodies in the blood that are indicative of the condition.
Understanding Rheumatoid Arthritis Tests
RA is an autoimmune disease that primarily affects the joints. Diagnosing RA typically involves examining several factors, and blood tests play a crucial role in confirming the presence of the disease. The blood tests look for inflammation and specific blood proteins (antibodies) associated with RA. Here are some common tests performed:
Key Blood Tests for RA
| Test Name | What It Measures | Why It's Important for RA Diagnosis |
|---|---|---|
| Erythrocyte Sedimentation Rate (ESR) | Rate at which red blood cells settle at the bottom of a test tube in one hour | Elevated rates indicate inflammation in the body, including the joints |
| C-reactive protein (CRP) | Amount of C-reactive protein in the blood | Elevated CRP levels are another sign of inflammation in the body |
| Rheumatoid Factor (RF) | Presence of an antibody (RF) that can attack healthy tissues in the body | About 80% of people with RA test positive for RF |
How the Tests Help Diagnose RA
These tests, especially when combined with a physical exam and medical history, help doctors diagnose RA.
- Inflammation markers: Elevated ESR and CRP levels confirm that there is ongoing inflammation in the body.
- Presence of specific antibodies: A positive rheumatoid factor (RF) test suggests that the person might have RA.
Important Considerations
- Not Definitive: These tests alone do not confirm RA.
- Combined Approach: The diagnosis also considers other factors, like symptoms and X-rays.
- Other Tests: Doctors might order additional blood tests such as anti-CCP (anti-cyclic citrullinated peptide) to confirm diagnosis since not all individuals with RA test positive for RF.
