Body soreness and weakness feeling very tired may be caused by insufficient sleep time, anemia, insufficient blood supply to the brain and other reasons. 1. Insufficient sleep time: If you stay up late for a long time and sleep too little. The brain will be in a state of tension for a long time and not get enough rest, which will affect the blood circulation of many organs in the body, and this will lead to symptoms such as soreness and weakness and feeling very tired. 2. Anemia: If the daily diet is not regular, the food intake is too single, the intestinal function is relatively poor, etc., the blood is not supplemented to the body in a timely manner or the absorption is insufficient, benign anemia will occur, which will also lead to the body soreness and weakness and feeling very tired. 3. Insufficient blood supply to the brain: patients may suffer from cervical spondylosis, cardiovascular and cerebrovascular diseases, which will lead to insufficient blood supply to the brain, resulting in the symptoms of body weakness and tiredness. If the body is often weak and tired patients, you need to go to the hospital in time for examination, combined with the cause of the treatment.