The common causes of joint enlargement and deformation in the elderly are gout, osteoarthritis, rheumatoid arthritis, tumor and so on. 1. Gout: due to abnormal uric acid metabolism, urates are deposited in the joints to form gout stones, resulting in swollen and deformed joints, which often appear in the first toe and ankle joints. 2. Osteoarthritis: due to old age, obesity, physical labor and other reasons, resulting in joint cartilage damage, osteomalacia, resulting in joint swelling and deformation, most commonly found in the knee and hip joints. 3. Rheumatoid arthritis: Bone destruction due to long-term inflammation stimulation, causing joint swelling and deformation, which may be accompanied by joint pain, activity limitation, stiffness of joints in the morning fingers and other symptoms. 4. Tumor: such as chondrosarcoma, bone metastatic tumor, osteoid osteoma, etc. Tumor cell growth, destroying the normal bone, can appear joint swelling and deformation, which can appear in all joints of the body. There are many reasons that cause joint enlargement and deformation of the elderly, it is recommended to consult the doctor in time, improve the relevant examination, clarify the cause of the disease and carry out targeted treatment.