Generalized weakness at night may be caused by physiological factors, and may also be considered to be related to colds, hypothyroidism, hypokalemia, anemia and other diseases. 1. Physiological factors: often carry out heavy labor or high-intensity exercise, the body does not get enough rest, may feel weak at night. Frequent overtime work and long hours of sleep deprivation, resulting in decreased immunity, may also feel weak at night. 2. Cold and flu: cold and flu lead to upper respiratory tract infection, fever, the body produces a lot of lactic acid, the patient may feel generalized fatigue, aches and pains. 3. Hypothyroidism: In patients with hyperthyroidism, the thyroid gland synthesizes and secretes and releases more thyroid hormones, leading to an increase in the body’s metabolism, and the patient is prone to fatigue. Especially at night, the symptoms of fatigue are more obvious. 4. Hypokalemia: Decreased potassium content in the blood may lead to decreased muscle tone, which may cause symptoms such as pallor, weakness, chest tightness and shortness of breath. 5. Anemia: Insufficient blood volume in anemic patients may cause dizziness, panic and shortness of breath, chest tightness, loss of appetite, weakness and other symptoms. It is recommended to improve bad habits, ensure sufficient sleep, and if necessary, go to the general internal medicine department of the hospital to look for the causes of weakness and give appropriate treatment.