The left side of the breast for a while appeared burning, for a while good, the position is not fixed may be the emergence of mastitis, breast hyperplasia and breast tumors. 1. Mastitis: Breastfeeding patients will experience redness, swelling, heat, pain and other symptoms due to the blockage of the milk ducts and the decrease in the amount of milk secreted by the breasts, accompanied by a burning sensation in an irregular position in one breast. Non-breastfeeding patients are mainly due to bacterial infections, and the symptoms are similar to those of breastfeeding patients. 2. Breast Hyperplasia: patients with endocrine dysfunction due to high pressure of life and prolonged late night may cause breast swelling and discomfort, which may show burning sensation in one breast in an irregular position. 3. Breast tumor: if the tumor is small, the burning symptom is not obvious, when the volume of the tumor is increasing, the burning sensation of irregular position may appear, which may be accompanied by skin changes. When the patient has a burning sensation in the left breast for a while, and the position is not fixed for a while, he should consult the doctor in time and take treatment under the guidance and advice of the doctor.