There are more reasons for leg and knee pain, which may be related to bone and joint strain, osteoarthritis, synovitis and so on. 1. Osteoarthritis: chronic joint strain due to long-term standing, walking or overloaded sports, resulting in cumulative damage to the knee joint, as well as the leg and knee pain. 2. Osteoarthritis: due to long-term chronic strain or degenerative changes in the knee joint caused by aging, which can lead to deformation of the knee joint, hyperplasia, thinning of the cartilage, decreased function, and easy to appear leg and knee pain during exercise. 3. Synovitis: may be due to knee joint off injury, excessive exercise, etc., resulting in damage to the joint capsule, synovial tissue congestion and edema. This leads to the onset of synovitis, manifested in the phenomenon of leg and knee pain. Knee pain can also be seen in gout, rheumatoid arthritis and other causes, it is recommended to consult a doctor in a timely manner, follow the doctor’s instructions for further examination, with the help of the doctor to clarify the cause, and targeted treatment or treatment.