Rheumatoid arthritis is divided into acute, subacute, chronic and remission stabilization phases. Acute phase: Rheumatoid arthritis has an acute onset, with obvious swelling and pain in the joints, accompanied by mild edema in the peri-articular tissues, increased local temperature, pressure pain, joint effusion, and limited or completely immobile joint movement. Morning stiffness does not last more than one hour, or does not show morning stiffness due to pain. The duration of the disease ranges from 2-6 months to 1 year. Laboratory tests show an increased blood sedimentation and a positive rheumatoid factor. Radiographs of the joints show swelling, widening of the joint space and swelling of the soft tissues around the joints, and the bones become osteoporotic. The pathological changes at this stage are characterized by acute synovitis. After effective treatment, the inflammation of the joint may rapidly subside, the swelling and pain may disappear completely, or only slight pain and soreness of the joint may remain, which can be completely controlled for more than 1-3 years or cured. Subacute phase: The clinical manifestations of this phase are multi-joint swelling and pain, with repeated and alternating waves of remission and deterioration: morning stiffness in 1-6 hours; duration of the disease in 1-3 years; laboratory tests show persistent rapid increase in blood sedimentation, and rheumatoid factor is mostly positive; X-ray examination shows focal bone destruction, obvious osteoporosis or cystic changes, periosteal reaction, and mild narrowing of joint space. The pathological changes at this stage are the progression of acute synovitis, hemorrhagic vasculitis and granulation tissue, and the beginning of vascular opacification. This stage is inseparable from anti-rheumatic analgesics, which cannot effectively relieve pain and stiffness when the amount is small or the interval is long (more than 6 hours); once the drug is stopped, joint and systemic symptoms rapidly worsen, blood sedimentation rises back and rheumatoid factor turns positive, but it can be controlled for 3 months to 3 years after reasonable treatment. Chronic phase: This phase is mostly transformed from subacute phase. Multiple joint swelling and pain occur one after another with almost no remission period, but the degree of joint swelling and pain is relatively mild, and joint dislocation, deformation and ankylosis gradually occur unknowingly, forming a typical rheumatoid hand or rheumatoid foot. The muscles around the joints are atrophied and the general condition is poor, mostly with wasting, anemia or severe visceral damage and enlarged liver, spleen and lymph nodes. Morning stiffness is more than 6 hours, and the duration of the disease is usually more than 3 years and can last for decades. Laboratory tests show increased or normal blood sedimentation and persistent positive rheumatoid factor. x-ray examination shows extensive osteoporosis. Bone destruction is marked and polyarticular, with erosion and fusion of the joint surfaces, significant narrowing or loss of joint space, joint dislocation, deformation, hyperplasia, and ankylosis. Pathology reveals vascular opacities invading cartilage and bone, and severe destruction of cartilage and bone tissue. Treatment at this stage is more difficult, and the effect of general anti-rheumatic drugs is mostly unstable, but with reasonable treatment, bone destruction can be partially repaired. Comprehensive treatment can delay and control the progress of lesions. The remission and stabilization phase: After effective and reasonable treatment of patients in the acute, subacute and chronic phases, most patients can enter the remission phase. In the remission phase, joint swelling subsides, pain is significantly reduced, there may be slight pressure pain, muscle atrophy and joint movement limitation improve, morning stiffness is less than 30 minutes; blood sedimentation and other laboratory indicators are reduced or significantly improved; joint X-ray examination has improved. At this stage, the patient’s lesions are quiescent or slowly progressing. Small doses of drugs or intermittent treatment are still needed clinically. In the stable stage, the joint swelling and pain can disappear completely, and the limitation of joint movement and muscle atrophy can also improve or disappear, and the lesion can be stable for 3 months to 3 years, and some patients can be cured.