Each breast contains a rich source of glandular tissue, encased in layers of fat cells, connective tissue, blood vessels, lymph nodes and nerve endings. The glandular tissue of the breasts contains bulb-like lobules, which produce breast milk, as well as ducts, which carry that milk to the nipple. Breast tenderness and soreness can occur due to changes in the normal growth of breast tissue, either due to natural changes within the body or due to a disease.
Hormone Fluctuations
Hormone fluctuations, such as those that occur in pregnancy, can lead to breast tenderness and soreness. Cells within the breast respond to the levels of hormones in the blood, such as estrogen and progesterone. Upon sensing these hormones, the cells begin to proliferate, leading to an increase in the mass of the glandular tissue within the breast. These waves of glandular growth are often accompanied by breast tenderness, as the new glandular tissue can place pressure on surrounding nerves, causing pain until the breast adjusts to its new shape. The Ohio State University Medical Center indicates that these hormone fluctuations can cause breast tenderness and soreness in early pregnancy to allow for lactation, as well as during the menstrual cycle.
Breast Fibroids
Another possible cause of breast soreness and tenderness is a fibroid tumor, a type of benign, or noncancerous, breast growth. These fibroid tumors, also called fibrocystic breast disease, occur when the breast over-responds to hormonal fluctuations, leading to exaggerated cycles of breast growth. As a result, women with fibroid tumors develop lumpy breasts, corresponding to glandular tissue growth, as well as pain and swelling in the breasts. The University of Maryland Medical Center indicates that patients with fibrocystic breast disease may control breast pain with medication, wearing a supportive bra and applying ice packs to the sore breast. In most cases, the symptoms of fibrocystic breast disease resolve during menopause.
Inflammatory Breast Cancer
In some cases, soreness and tenderness of the breasts may indicate a serious underlying disorder, such as a malignancy. One such disease is inflammatory breast cancer, an aggressive form of cancer that leads to pain in the affected breast. During inflammatory breast cancer development, cancer cells begin to block the lymphatic vessels within the breast, preventing the normal flow of lymphatic fluid. The fluid begins to accumulate in the breast, leading to painful breast swelling and redness, according to the National Cancer Institute. Patients with inflammatory breast cancer must undergo aggressive cancer treatment, which may include surgery, chemotherapy, hormone therapy or radiation.
