Generalized weakness when laughing is mostly a normal physiological condition, but it may also be caused by diseases, such as autonomic dysfunction, hypoglycemia and so on. 1. Physiological situation: Laughing or laughing for a long time can lead to hyperventilation, making the brain lack of oxygen, causing generalized weakness. In addition, laughing can relax the mood and reduce stress, which will also relax the muscles. 2. Autonomic dysfunction: Symptoms of sympathetic hyperfunction can exist. When laughing, the heart rate will be accelerated, the body’s oxygen consumption will be increased, the symptoms of generalized weakness may occur, and headache and other discomforts will also occur. 3. Hypoglycemia: Laughing consumes the body’s energy, and if the patient suffers from hypoglycemia, which leads to insufficient body functions, generalized weakness may occur, often accompanied by dizziness. If the symptoms of generalized weakness occur frequently when laughing, you should consult a doctor in time.