Rheumatoid arthritis is a systemic autoimmune disease characterized by chronic erosive arthritis. The lesions of rheumatoid arthritis are characterized by synovitis and the resulting destruction of joint cartilage and bone, which ultimately leads to joint deformity. Without regular treatment, approximately 75% of patients become disabled within 3 years. Rheumatoid arthritis can develop in all ages, with a peak age of about 30 to 50 years, and generally more women than men. Clinical manifestations and diagnosis 1, routine examination (1) blood routine: about 30% of patients with rheumatoid arthritis combined with anemia, mostly orthocytic orthochromic anemia. Platelets are elevated during the active phase of the disease. In a few cases, there is a decrease in white blood cells, such as Felty syndrome. (2) Acute phase reactants: Most patients with rheumatoid arthritis have increased sedimentation and elevated C-reactive protein during the active phase, which can return to normal when the disease is in remission. 2, autoantibodies (1) rheumatoid factor (RF): 75%-85% of patients have positive serum rheumatoid factor, and correlate with the disease and extra-articular manifestations. (2) Anti-citrullinated protein antibody (ACPA): Anti-citrullinated protein antibody is a general term for a class of autoantibodies containing citrullinated epitopes, which has high sensitivity and specificity for the diagnosis of rheumatoid arthritis and is closely related to the condition and prognosis of rheumatoid arthritis. 3.Synovial fluid examination The joint fluid of patients with rheumatoid arthritis is generally inflammatory in character, and the total number of white blood cells can reach (10~10000)×10/L, and the cell classification is dominated by neutrophils. 4.Imaging examination (1)X-ray examination: early X-ray shows swelling of soft tissues around the joint and osteoporosis near the joint; with the progress of the disease, joint surface destruction, joint gap narrowing, joint fusion or dislocation may occur. (2) Magnetic resonance imaging (MRI): MRI is superior to X-rays in showing joint lesions and has been increasingly used in the diagnosis of rheumatoid arthritis in recent years. MRI can show synovial thickening, bone marrow edema and mild joint surface erosion at the beginning of the inflammatory response of the joint, which is beneficial for the early diagnosis of rheumatoid arthritis. (3) Ultrasound: High-frequency ultrasound can clearly show the joint cavity, synovial membrane, bursa, joint cavity fluid, articular cartilage thickness and morphology, etc. Color Doppler flow imaging (CDFI) and color Doppler energy map (CDE) can visually detect the distribution of blood flow within the joint tissue and reflect the synovial membrane hyperplasia with high sensitivity. Ultrasonography can also dynamically determine the amount of joint fluid accumulation and the distance from the body surface, which can be used to guide joint puncture and treatment. Treatment The goal of rheumatoid arthritis treatment is to control the disease and improve joint function and prognosis. The principles of early treatment, combination of drugs and individualized treatment should be emphasized. Treatment methods include general therapy, drug therapy and surgical and other treatments.