The common causes of night sweating in the second half of the night (abnormal sweating after going to sleep and stopping after waking up) include yin deficiency and fire exuberance, insufficient blood in the heart, and deficiency of both qi and yin. 1. Excessive Yin deficiency and fire: Excessive Yin deficiency and fire will lead to the inability of Yin fluid to meet the basic needs of the human body, and it may also lead to the suppression of Yang heat of the normal life activities of the human body, which will lead to pathological conditions, so it will lead to sweating in the second half of the night, and it may be accompanied by the symptoms of five heart-heat (the heart of the two hands and the two hearts of the two feet are hot, and consciously feel that the heart and chest are hot), and emaciation and other symptoms. 2. Insufficiency of heart blood: insufficiency of heart blood is also one of the causes of night sweating in the second half of the night, due to insufficiency of heart blood, the role of moistening and nourishing the heart as well as transforming the heart and spirit will be affected, so it will lead to night sweating in the second half of the night, and some of the patients may also have palpitations, colorlessness and other symptoms. 3. Qi and yin deficiency: Qi and yin deficiency may also cause night sweating in the second half of the night, which is usually caused by certain diseases or improper diet, resulting in the damage of yin and yang, leading to qi and yin deficiency, and some patients, in addition to night sweating in the second half of the night, may also appear to be emaciated. There are many reasons for night sweats in the second half of the night, so it is recommended to consult a doctor in time, according to the cause of targeted treatment.