Rheumatoid arthritis (RA) is a chronic, predominantly inflammatory synovitis systemic disease of unknown etiology. It is characterized by polyarticular, symmetric, aggressive joint inflammation of the small joints of the hands and feet, often accompanied by extra-articular organ involvement and positive serum rheumatoid factor, which can lead to joint deformity and loss of function. The disease can be considered to be in active stage if 4 or more of the following criteria are met: 1. morning stiffness for more than 15 minutes; 2. feeling weak within 6 hours of waking up in the morning; 3. joint pain; 4. pressure pain or moving pain in more than 2 peripheral joints; 5. synovial swelling in more than 2 peripheral joints; 6. blood sedimentation (Weil’s method): ≥20mm/1h in men and ≥30mm/1h in women.