Body sinking and heavy legs are generally considered to be generalized weakness, with the following common causes: 1. malnutrition, hypoglycemia, long periods of not eating, partial eating or irregular meals, resulting in inadequate nutrient and energy intake, resulting in weakness of the limbs, dizziness, cold sweats and other hypoglycemic manifestations. 2. cardiovascular and cerebrovascular diseases, such as transient cerebral ischemic attacks, which can result in dizziness, weakness and even fainting. 3. chronic anemia. The patient with anemia will have weakness in the limbs. 4, spinal cervical spondylosis, intervertebral disc compression of the spinal cord causing numbness, pain and even weakness in the limbs. 5, hypokalemia, low potassium will cause a decrease in muscle tone causing generalized weakness. 6, prolonged strenuous exercise, muscle tension for a long time, tissue ischemia, hypoxia, anaerobic enzymes produce a large amount of acid, stimulating muscle weakness and pain.