The diagnosis of rheumatoid arthritis is mainly based on the history of hemolytic streptococcal infection 1-4 weeks before the onset of the disease, acute wandering arthritis, often accompanied by other manifestations of rheumatic fever such as myocarditis, annular erythema, subcutaneous nodules, etc., a significant increase in the agglutination potency of anti-streptococcal hemolysin “0” in the serum, positive throat swab culture and blood leukocytosis. The serum is significantly elevated in anti-streptococcal hemolytic “0” agglutination, positive pharyngeal swab culture and leukocytosis. Anti-streptococcal (anti-streptococcal hemolysin) is an antibody that appears in the serum after the human body is infected with group A hemolytic streptococci. Nearly 85% of patients with rheumatoid arthritis have elevated anti-chain, usually above 1:800. Of course, this antibody can gradually decline after recovery from rheumatoid arthritis. In addition to increased anti-chain, laboratory tests may also reveal the following abnormalities in rheumatoid joints: 1. The peripheral blood leukocyte count is elevated, mostly above l0×109/l (i.e., 10,000/mm3). 2. Elevated blood sedimentation and C-reactive protein. Blood sedimentation and C-reactive protein are usually indicators of various inflammatory conditions. In the acute phase of rheumatoid arthritis patients, blood sedimentation can reach more than 90 mm/hour; C-reactive protein is also above 30 mg/l (30 micrograms/mL). After the acute phase (about 1-2 months), it gradually returns to normal. 3, joint fluid examination, often exudate, white blood cell count can be close to normal in mild cases, up to 80×l09/liter (80,000/mm3) or more in severe cases, most of which are neutrophils. Bacterial culture is negative. 4, rheumatoid factor and anti-nuclear antibody are negative. 2, rheumatoid arthritis characteristics 1, pain duration is short, generally 12-72 hours, the longest is only 3 weeks, and mostly large joints, such as the knee, elbow, shoulder and other joints. 2, wandering pain, that is, after the pain of a joint has improved or has not yet significantly improved, another joint is attacked and pain occurs. 3.Joint pain is accompanied by redness, swelling, pressure pain around the joint, and refusal to press. 4.Symmetrical pain, the lesion can invade the same joint of both limbs at the same time, for example, both knees and both elbows can have pain at the same time. 5. The pain may be accompanied by annular erythema or subcutaneous nodules on the skin. 6.The pain may occur in more than one joint at the same time. 7.After the pain subsides, no joint ankylosis or deformity remains, and joint function can be restored. 8, rheumatoid arthritis is a metabolic disease is one of the main manifestations of rheumatic fever. Most of the acute fever and joint pain onset, the typical performance is mild or moderate fever wandering polyarthritis, the affected joints are mostly knee, ankle shoulder, elbow, wrist and other large joints commonly transferred from one joint to another, the lesion localized red, swollen burning, severe pain, some patients also have several joints at the same time atypical patients only have joint pain and no other inflammatory manifestations, acute inflammation generally in 2-4 weeks The acute inflammation usually subsides in 2-4 weeks, leaving no sequelae but often recurrent. If rheumatic activity affects the heart, myocarditis or even heart valve lesions may occur.