If you feel weak and weak, it is often related to the following reasons: 1, may be due to overexertion, such as some patients do very strenuous, continuous activities, such as running marathons and other sports beyond the limits of the body, will make the body feel very tired and weak within a period of time. 2, may be caused by long-term non-exercise, in fact, this is another kind of overexertion The situation. In modern society, many patients need to sit and stand for a long time or keep a certain posture fixed for professional reasons, while some patients are due to poor living habits, need to use the computer for a long time, which will lead to insufficient exercise for patients. Once the exercise is not enough, it may lead to the lower limbs of the blood circulation slowed down and disuse muscle atrophy, then the patient will feel the obvious leg weakness when they get up and move. 3, there may be due to osteoporosis caused by. Osteoporosis may seem relatively far from normal adults, but it is not. Osteoporosis can occur in patients of all ages, and the disease often appears in adults as weakness and leg weakness without any precipitating factors. 4. The above-mentioned condition may also be caused by related joint inflammation, such as bilateral knee joint osteoarthritis or synovitis, which can lead to weakness of the lower limbs.