What Causes Breast Enlargement and Pain?

Breast enlargement and pain require careful observation for concurrent signs such as localized redness and warmth. Certain inflammatory conditions can readily cause local tissue swelling, resulting in tenderness upon palpation—particularly in lactating women. The presence of a firm lump in the breastfeeding breast should raise suspicion of milk stasis. So, what causes breast enlargement and pain? Below, we address this question.

Causes of Breast Enlargement and Pain

1. Mastopathy (Benign Breast Hyperplasia)

Hard nodules formed by mastopathy may enlarge, become tender, and swell under hormonal stimulation. Mild cases may be managed with oral medication; severe cases may benefit from surgical excision of the nodules. Pain is typically centered on the nodule and may radiate to the ipsilateral axilla or shoulder/back region. Some patients report nipple pruritus or pain. Symptoms often appear or worsen several days before menstruation and subside or resolve after menses. Pain intensity may fluctuate with emotional changes.

2. Mastitis (Breast Inflammation)

Pain typically intensifies upon breast palpation. Concurrent symptoms include nipple swelling and marked tenderness over the affected breast tissue. Without timely treatment, pain progressively worsens and may evolve into pulsatile pain. Skin over the affected area may also become erythematous. In acute abscess formation, localized, well-defined pain occurs, accompanied by a fluctuant mass, fever, chills, and generalized malaise.

3. Trauma to the Breast

Blunt chest trauma may injure breast tissue and cause hematoma formation, leading to painful breast enlargement. Physiological factors—including puberty, pregnancy, and the postpartum period—may also cause sharp, stabbing breast pain. Environmental and emotional stressors—such as sudden temperature drops, excessive anxiety, or tension—can similarly trigger this symptom. In contrast, pain caused by breast cancer tends to be persistent and progressively worsening, occurring unpredictably and without discernible pattern. It may be accompanied by nipple-related abnormalities, including palpable masses and asymmetry.

The above outlines the common causes of breast enlargement and pain. We hope this information is helpful to you.