Pain on the side of the breast can be caused by several different factors, but most of the conditions responsible for this type of pain are not serious. Some women worry about breast cancer when they experience breast pain, but this is not usually the cause. Women who experience chronic breast pain should talk to a healthcare professional about the possible causes and receive regular mammograms to identify cysts and growths that could turn cancerous. The most common causes of pain are hormonal changes, fibrocystic breasts, costochondritis, and improperly-fitting bras.
Hormonal changes due to the normal hormone fluctuations associated with the menstrual cycle or hormone changes in response to stress are the most common causes of pain on the side of the breast. The breasts often swell just prior to menstruation, which can lead to pain along the sides, and may cause the breasts to feel tender to the touch or just generally achy. This type of breast pain usually subsides after the woman menstruates, and it can be treated with over-the-counter pain relievers, such as acetaminophen, or nonsteroidal anti-inflammatory drugs, such as ibuprofen. Oral contraceptives help regulate hormone levels and may also be effective at relieving this type of pain.
Fibrocystic breasts are an extremely common condition, affecting more than half of women at some point. The condition is usually caused by non-cancerous cysts, scar tissue, or an overgrowth of cells in the milk ducts that cause the breasts to swell and feel thick or lumpy. Pain on the side or in the upper area of the breast are the most common symptoms of this condition. The symptoms typically fluctuate with menstrual cycle patterns, though the condition can persist in postmenopausal women taking hormone therapy. Medications to control pain are usually sufficient, though minor surgery to drain or remove the cysts is sometimes necessary.
Costochondritis, an inflammation of the cartilage in the chest, can also be responsible for pain on the side of the breast. While the exact cause of the condition is not known, it often results from injury to the chest, infection, or upper respiratory problems. Costochondritis causes pain where the ribs meet the sternum, and it may radiate to the insides of the breasts. Treatment includes muscle relaxants, anti-inflammatory drugs, and gentle exercises to stretch the chest muscles.
Improperly-fitting bras can cause pain on the side of the breast from squeezing or poking the soft tissues. Women who experience breast pain with no other apparent cause should be professionally measured to make sure they are buying the correct bra size. Wearing supportive sports bras may also help decrease symptoms.