Possible Causes of Breast Pain 

Intermittent breast pain and discomfort can be a regular part of a woman's menstrual cycle and is usually nothing to worry about. Sudden pain may be a sign of mastitis, another painful but benign and treatable condition most commonly related to breastfeeding. Cracked nipples can allow bacteria from the baby's mouth to enter the breast and cause an infection. Mastitis usually requires a prescription for antibiotics, so if you experience pain and are nursing, see a doctor. 

It's possible for breast pain to be attributed to some fairly scary-sounding conditions that usually are benign. But if you suspect any of the following or feel any lumps during a breast self-exam, it is important to see a doctor to confirm diagnosis and treatment, if needed. Some conditions may increase women's risk for breast cancer. In that case, it's important to be vigilant about your breast health. Other non-cancerous breast conditions that may cause pain include: 

• Hyperplasia – An overgrowth of cells in breast ducts that usually can be seen with a mammogram. More advanced cases may increase breast cancer risk.
• Cysts – Lumpy, fluid-filled sacs that most often aren't cancer. They are less firm than tumors but should be checked out. Cysts usually require no treatment unless they are large or painful.