Yin deficiency and fire is a deficiency heat disorder that occurs when the patient’s yin deficiency leads to hyperactivity of yang, which can cause insomnia, mouth ulcers, toothache, blood in urine, constipation and other consequences. Most of the long-term yin deficiency fire is caused by the loss of essence and blood, resulting in internalized deficiency heat, which causes insomnia. The reason why yin deficiency fire leads to insomnia is that the deficiency fire is pressed in the body, leading to the leakage of yang qi on the body, which results in the five heart heat (heat in the hearts of the two hands and the two feet, and self-consciousness of the heart and chest), and the mind and spirit are not at peace, which results in the symptom of insomnia. The symptoms of mouth ulcers and toothache are also usually caused by Yin deficiency and fire exuberance. In addition, Yin deficiency and exuberant fire can also lead to the body of qi and blood, so that the patient appears to have symptoms of blood in the urine, Yin deficiency so that the intestinal tract can not be nourished by Yin fluid, may also cause constipation. Patients in the long-term symptoms of yin deficiency and fire, should adjust their diet structure, eat more light and easy to digest food, as well as appropriate exercise exercise. If necessary, they should go to the hospital for examination and treatment under the guidance of the doctor.