Depends on what you say. Generally speaking, if you don't exercise regularly, your knees will hurt after exercise or excessive exercise. This is the relationship between not fully warming up before exercise and not moving joints and relaxing muscles after exercise. If it happens to teenagers, it is a normal phenomenon and a "growing pain", which will be relieved after appropriate reduction of exercise and calcium supplementation.

If it is frequent, it may be osteoarthrosis, and the main clinical symptoms are: pain, dysfunction, deformity and so on. The early performance is pain and discomfort at the joints after a long walk, which will be relieved after rest. If it is an injury between the buttocks and thighs, the pain of going up and down the stairs will be aggravated. Feel stiff joints after rest. Sitting down and getting up suddenly can cause severe joint pain. Gradually, the walking ability will become shorter and the pain will last longer. It will develop to rest and the pain will not stop. The nature of pain can develop from soreness to tingling, and in severe cases, it can lead to difficulty in walking or limping.

There is also a popliteal cyst, the main clinical symptoms are: no pain at first, or just some swelling of the knee joint, and some patients have weakness of the lower limbs. When it develops seriously, it will form a large mass, which will limit knee flexion. I can feel a spherical elastic substance in the popliteal fossa, with smooth surface, soft texture, no obvious tenderness and a sense of movement. The lump will become hard and obvious when the knee is stretched.

There is knee synovitis. The main clinical symptoms are repeated swelling and pain of knee joint or chronic diffuse swelling of knee joint, with no systemic symptoms. Due to the synovial fluid oozing from the joint cavity, the tarsal bone feels floating. On both sides of the tarsal ligament, the knees are bulging and full, and they feel like two soft things. Seriously, it's hard to walk.