During lactation, most mothers often experience nipple pain, which often intensifies after breastfeeding. If the pain worsens, breastfeeding should be stopped, and a detailed breast examination should be conducted at the hospital. Many mothers experience nipple pain due to pathological reasons rather than physiological ones. These include mastitis and breast hyperplasia, both of which occur with a relatively high frequency.

Pathological Reasons

(1) Breast Hyperplasia: The primary cause of breast hyperplasia is endocrine hormone imbalance. Breast tissue is highly sensitive to hormonal changes, and breast pain is often the initial symptom for patients seeking medical attention for breast hyperplasia. Breast hyperplasia can be accompanied by breast lumps, menstrual irregularities (delayed, reduced volume, light-colored menstrual flow), nipple discharge, and changes in emotional state (irritability, anxiety, and stress). Therefore, it is important to distinguish normal breast pain from breast hyperplasia to avoid delayed treatment.

(2) Mastitis: Mastitis can be divided into lactational mastitis and non-lactational mastitis. Acute mastitis commonly occurs in lactating women, especially first-time mothers. It is an acute inflammatory condition caused by bacterial infection during lactation, typically presenting with redness, swelling, warmth, and pain in the affected area. Systemic symptoms may include chills, fever, fatigue, and poor appetite. If a breast abscess forms, ultrasound examination may reveal fluid levels, and pus may be aspirated through needle aspiration.

(3) Breast Cancer: Breast cancer is most common in women between 40 and 60 years old, with a higher incidence around menopause. Early-stage breast cancer is often painless, and painful breast cancer is often indicative of later stages. Studies have shown that postmenopausal women with breast pain accompanied by glandular thickening have a higher detection rate for breast cancer. Tumors accompanied by inflammation may also cause pain or tenderness. In late-stage tumors, if the nerves are invaded or the axillary lymph nodes are enlarged, compression or invasion of the brachial plexus may result in shoulder pain. Breast cancer is also associated with breast lumps, nipple discharge, nipple changes, skin changes, and axillary lymph node enlargement.

Physiological Reasons

(1) Breast Pain during Adolescence: Breast development during adolescence begins with nipple protrusion, followed by the formation of round, hard nodules under the nipple, resembling the size of peas to beans, accompanied by mild pain. This pain typically resolves spontaneously as the breasts mature during puberty.

(2) Premenstrual Breast Pain: More than half of women experience breast fullness, hardness, and tenderness before menstruation. In severe cases, even slight vibration or impact to the breasts can cause significant discomfort, and the presence of granular or nodular sensations may become more prominent. These symptoms usually resolve after menstruation.

(3) Breast Pain during Pregnancy: Some women may experience breast hyperplasia and enlargement around 40 days after pregnancy, resulting in breast pain. This pain can persist throughout the entire pregnancy in severe cases.