Breasts feel a little hot, may be some physiological phenomenon, may also be the manifestation of certain diseases, such as mastitis, allergies, etc., should be timely consultation to find out the cause of the disease. 1. Physiological factors: the secretion of estrogen in the body before the onset of menstruation is considered to stimulate the proliferation of breast ducts and connective tissue, which may cause a little hot feeling in the breasts, or even swelling of the breasts. 2. Pathologic factors: (1) Mastitis, can be divided into lactation and non-lactation, lactation is mostly seen in postpartum lactating women, non-lactation can occur at any age, but is more common in young women. Usually the main manifestations are breast pain, redness, swelling and fever, and further development can form breast abscess. (2) Allergy due to contact of the skin of the breasts with allergens, such as breasts coming into contact with poor quality corsets or creams, resulting in itching, pain, and heat in the breasts. This symptom alone is not enough to diagnose the disease; it may also be caused by other factors, such as breast cancer or neuritis between the ribs. It is recommended that if physiological causes are ruled out, you should consult a doctor to clarify the cause and give targeted treatment.