The stabbing pain inside a woman’s right breast may be caused by cystic hyperplasia, acute mastitis, premenstrual syndrome and other reasons. 1. Cystic hyperplasia: Cystic hyperplasia is a common benign disease in women of childbearing age, usually caused by endocrine hormone disorders. Patients usually have breast tingling, and the pain worsens before menstruation and relieves significantly after menstruation, and may also be accompanied by breast hyperplasia nodules. 2. Acute mastitis: Acute mastitis often occurs during breastfeeding, due to acute inflammation in the mammary gland caused by the accumulation of milk, the patient will have obvious tingling or pressure pain in the breast. 3. Premenstrual Syndrome (PMS): Before the onset of menstruation, women will experience some clinical symptoms, which can be manifested as headache, breast tenderness, abdominal distension, irritability, anxiety, and so on. Usually seven days to half a month before the menstrual period, gradually aggravated, after the onset of menstruation symptoms will disappear. Women’s right side of the chest inside the stabbing pain can be caused by a number of reasons, it is recommended that the patient timely to the regular hospital for further examination, to clarify the cause of the disease and then targeted treatment.