Many causes of pain or tenderness in the breast are the result of natural body processes such as menstruation and pregnancy, as well as puberty in both males and females, according to the National Institutes of Health. Medications, disease, infection and structural abnormalities may cause breast pain, but breast cancer normally does not cause discomfort. Cyclic breast pain normally comes and goes with the menstrual period. Diagnosis of non-cyclic breast pain--not linked with menstruation--depends on the patient's medical history, a breast examination and, often, testing, such as an ultrasound, mammogram or breast biopsy, according to the Mayo Clinic.
Breast Anatomy
Non-cyclic breast pain--not related to the menstrual cycle--is often related to the size or anatomy of the breast, according to the Mayo Clinic. Large breasts are often painful and cause pain in the neck, shoulders and back as well, according to the Mayo Clinic. Abnormalities of the breast structure due to cysts, injury or previous surgery can cause pain. Pain originating in the heart, chest wall, muscles or joints can also radiate into the breast.
Reproduction
Cyclic breast pain is associated with the menstrual cycle, according to the Mayo Clinic. Many patients, especially those with fibrocystic disease--lumps and bumps in the breast--experience breast tenderness before their menstrual periods, notes the National Institutes of Health. Breast tenderness is common in the first three months of pregnancy, as well. Since women in the later months of pregnancy, as well as those who are post-menopausal, have little or no breast pain, it is possible that hormones are responsible for cyclic breast pain, but further research is needed, according to the Mayo Clinic. Breast tenderness is common after childbirth and during breastfeeding, as well as during puberty.
Medications
Certain medications, including digitalis, methyldopa, spironolactone, chlorpromazine and certain diuretics, cause breast pain, according to NIH. Hormones, infertility treatments, antidepressants such as fluoxetine and sertraline are also associated with breast pain, according to the Mayo Clinic.
Infection
Breasts normally become tender and swollen with milk after childbirth, but excessive pain during the first few weeks of breastfeeding can be caused by mastitis, an infection of the breast tissue, according to the Mayo Clinic. Bacteria enter through breaks in the skin or nipple and multiply, causing pain, redness, swelling and sometimes fever and chills. Women at risk for developing mastitis include those with sore or cracked nipples and those whose breasts do not empty completely during breastfeeding.
Diseases
Shingles or herpes zoster on the skin over a breast can cause pain that is felt in the breast, according to NIH. Alcoholism with liver damage is also associated with breast pain. Breast cancer, however, is an unlikely cause of pain in the breast.
