There are many reasons for physical fatigue and weakness, both physiological, such as prolonged late night, overwork, pregnancy; there are also pathological, such as anemia, hyperthyroidism, diabetes and so on. 1. Physiological factors (1) Physical fatigue: prolonged late night, overwork and other reasons, easy to cause physical fatigue, is a normal physiological phenomenon, usually pay more attention to rest, can be gradually relieved. (2) Women’s early pregnancy reaction: early pregnancy due to the rise in hormone levels in the body of women can be manifested as physical fatigue and weakness, which is a normal physiological phenomenon. 2. Pathological factors (1) Anemia: lack of red blood cells leads to lack of oxygen in the muscles or nervous system, and the lack of oxygen in the body causes fatigue, which is usually manifested as pale skin and mucous membranes, drowsiness, dizziness, lack of concentration, and memory loss. (2) Hypothyroidism: Patients with hypothyroidism suffer from fatigue accompanied by chills, slow heart rate, loss of appetite and other symptoms. (3) Diabetes mellitus: When blood sugar is too high, the body’s utilization of sugar is impaired, causing symptoms of fatigue and weakness. (4) Cardiovascular diseases: Diseases such as atherosclerosis and hypertension lead to insufficient supply of effective circulating blood, resulting in ischemia and hypoxia, leading to fatigue and weakness, accompanied by chest pain, palpitations, shortness of breath and other symptoms. The symptoms of fatigue and tiredness should be based on the severity of the condition and relevant medical history, and promptly go to a regular hospital, and give targeted treatment after the doctor clarifies the cause of the disease.