Rheumatoid arthritis is a multisystemic inflammatory autoimmune disease that involves mainly peripheral joints. The disease has a global distribution and its etiology is unknown. It may be related to bacterial and viral infections, genetic, endocrine, metabolic, occupational, psychological and social environmental differences, nutritional and geographic factors, and has a chronic, symmetric, multisynovial arthritis and extra-articular lesions as its main clinical manifestations. The disease mainly affects small joints, especially the hand joints, and is symmetrical in distribution. In the early stages, the affected joints are painful, swollen, and have decreased function, and the disease has a continuous and recurrent course. The systemic manifestations of rheumatoid arthritis include fever, malaise, general malaise, pericarditis, subcutaneous nodules, interstitial lung lesions, arteritis, and peripheral neuropathy, in addition to joint lesions. In the broader sense, rheumatoid arthritis includes a wide range of systemic lesions in addition to inflammatory lesions in the joints. The American College of Rheumatology (ACR) and the European Union for the Control of Rheumatic Diseases (EULAR) jointly conducted a 3-year research project with the aim of redefining diagnostic criteria for rheumatoid arthritis (RA). in October 2009, the 73rd Annual American College of Rheumatology announced new classification criteria for RA: a patient is clearly diagnosed with rheumatoid arthritis if he or she has a score of 6 or more on the following criteria Rheumatoid arthritis. 1.Joints involved: 1 medium to large joint (0 points); 2-10 medium to large joints (1 point); 1-3 small joints (2 points); 4-10 small joints (3 points); more than 10 small joints (5 points). 2. Serology: negative for rheumatoid factor and anti-cyclic citrullinated peptide antibodies (0 points); at least one of the two tests is positive for low titer. Low titer defined as above the upper limit of normal but not higher than 3 times the upper limit of normal (2 points). At least one test positive for high titer, e.g. titer above 3 times the upper limit of normal (3 points). 3, duration of synovitis: less than 6 weeks (0 points); 6 weeks or longer (1 point) 4. Acute phase reactants: normal C-reactive protein and erythrocyte sedimentation rate (0 points); abnormal C-reactive protein or hematocrit (1 point). The previous criteria relied excessively on disease progression indicators such as joint destruction and subcutaneous nodules. The new criteria incorporate more hematological indicators such as anti-cyclic citrullinated peptide antibodies, C-reactive protein and blood sedimentation in addition to the usual indicators such as joint pain and swelling; to help clinicians confirm the diagnosis earlier before patients develop chronic irreversible joint destruction. To ensure that the disease can be treated adequately and reasonably in the early stages of the disease, early detection and early treatment can well control the development of arthritis, prevent and reduce joint destruction, maintain the function of the affected joints, and significantly improve the quality of life of patients.