More and more people are suffering from osteoarthritis, and it is common in people over the age of 40. Osteoarthritis is particularly prevalent in the knee joint and usually only causes symptoms in the joint without systemic symptoms such as fever, weight loss, or rash. Typical symptoms of osteoarthritis of the knee are as follows: 1. Knee pain Joint pain almost always starts gradually and progresses slowly. The pain is recurrent and mild at times. The pain is usually associated with joint movement, often worsens with activity, and can cause claudication. The pain seems to be related to temperature, air pressure, environment and emotion, and is aggravated by humidity, autumn and winter, and weather changes, which is why it is called “old cold leg”, or “weather station”. In the early stages of the disease, walking is fine, but after sitting for a few minutes, the knee joint will become stiff and painful. As the disease progresses, even simple daily activities can cause pain, even at rest. In advanced stages, the pain can persist and be heavier at night than during the day, even waking up in pain during the night. 2. Knee stiffness Knee stiffness often occurs when a posture or position is changed after a long period of time, such as when waking up in the morning, or when standing up after a long period of sitting, and it takes a while to move the joint to stretch. Generally, joint stiffness in osteoarthritis does not last more than 30 minutes. Osteoarthritis can lead to a reduction in the range of motion of the knee joint, i.e., “can’t bend” or “can’t straighten”. Pain can occur when the knee joint reaches its own limits of motion. 4. Sometimes there is a grinding sound in the knee joint. 5. Bone spurs formed by osteophytes can usually be seen on x-ray. 6. Occasionally, there is swelling and fluid accumulation in the knee joint because patients with osteoarthritis of the knee joint are sometimes accompanied by synovial inflammation, which causes joint swelling and fluid accumulation. 7, after the knee joint swelling bone hyperplasia (bone superfluous) caused by the joint appearance swelling deformation. 8, Some patients have inversion or valgus deformity of the knee.