How is rheumatoid arthritis diagnosed and what tests are commonly used?

Rheumatoid arthritis (RA) diagnosis involves a combination of:

1. Medical history: Assessing symptoms, duration, and impact on daily life.
2. Physical examination: Evaluating joint tenderness, swelling, and range of motion.
3. Laboratory tests:
– Rheumatoid factor (RF): Measures antibodies against the body’s own tissues.
– Anti-citrullinated protein antibody (anti-CCP): Detects specific antibodies associated with RA.
– Erythrocyte sedimentation rate (ESR): Measures inflammation.
– C-reactive protein (CRP): Assesses inflammation.
4. Imaging tests:
– X-rays: Evaluates joint damage and erosion.
– Ultrasound: Assesses joint inflammation and damage.
– Magnetic resonance imaging (MRI): Detailed joint evaluation.
5. Other tests:
– Complete blood count (CBC): Rules out other conditions.
– Blood chemistry tests: Evaluates overall health.

The American College of Rheumatology (ACR) and European League Against Rheumatism (EULAR) have established criteria for RA diagnosis, which include:

1. Morning stiffness lasting >1 hour
2. Swollen joints
3. Joint pain
4. Positive RF or anti-CCP
5. Elevated ESR or CRP
6. Radiographic evidence of joint damage