Rheumatoid arthritis is an autoimmune disease of unknown etiology. The disease invades joint cartilage, ligaments and tendons, causing destruction of joint cartilage, bone and joint capsule, which will eventually lead to joint deformities (most commonly ankylosis of the wrist joint, subluxation of the metacarpophalangeal joint, etc.) and loss of joint function due to atrophy and spasm of the muscles around the joint, making the patient unable to take care of himself/herself. Rheumatoid nodules around the joints or in the internal organs may also appear, and there may be lesions of the heart, lungs, eyes, kidneys, peripheral nerves, etc. The diagnosis of rheumatoid arthritis mainly relies on clinical manifestations, autoantibodies and X-ray manifestations. The main points of diagnosis are: 1. Morning stiffness: stiffness in and around joints lasting at least 1 hour in the morning (6 weeks or more of disease duration). 2.Multi-regional arthritis: arthritis in 3 or more regions (interphalangeal joints, metacarpophalangeal joints, wrists, elbows, knees, ankles and metatarsophalangeal joints, etc.) with concurrent soft tissue swelling, effusion or pain. 3.Hand arthritis: swelling and pain in at least one joint (6 weeks or more) in wrist, metacarpophalangeal or proximal interphalangeal arthritis. 4.Symmetrical arthritis: both joints are involved at the same time (not necessarily symmetrical when bilateral proximal interphalangeal joints, metacarpophalangeal joints and metatarsophalangeal joints are involved), and the disease lasts for 6 weeks or more. 5.Rheumatoid nodules: The doctor can observe subcutaneous nodules at the site of bony prominence, on the surface of the extensor muscle or around the joint. 6.Rheumatoid factor positive: any test method proves that the serum rheumatoid factor level is abnormal (the positive rate in the normal population is less than 5%). 7, X-ray examination: early arthritis X-ray manifestation of peri-articular soft tissue swelling, mild osteoporosis near the joints in the middle and late stages can be manifested as joint space narrowing, joint destruction, joint dislocation or fusion, and bone erosion or lesion joints with clear bone decalcification. Rheumatoid arthritis can be diagnosed when four of the above seven conditions are met and other arthritis is excluded.