Most common cause of mastitis

Milk stasis can follow missed feeds, a sudden change in feeding frequency, pressure from a tight bra, positioning difficulties or an ineffective latch. The breast may become tender, swollen, warm or red, and flu-like symptoms can occur. Inflammation does not always mean a bacterial infection, so forceful massage and excessive pumping can worsen tissue irritation. Mastitis can also occur outside breastfeeding, when a clinician should consider other causes.

[Breast Pain](/symptoms/breast-pain/) and [Painful Breastfeeding](/symptoms/painful-breastfeeding/) describe symptoms that may accompany mastitis but do not establish its cause.

Continue breastfeeding or expressing according to comfort and the baby’s needs; abrupt stopping can increase milk stasis. Use a comfortable position, avoid deep breast massage, and apply a cool pack for swelling. Rest, drink to thirst, and use a suitable pain reliever if it is safe for you. A [Lactation Consultation](/treatments/pregnancy-and-birth-care/lactation-consultation/) can check latch, positioning and feeding patterns. A clinician may prescribe antibiotics when bacterial infection is suspected or symptoms do not settle.

Arrange medical review if symptoms are worsening, you feel significantly unwell, or there is no improvement after supportive measures. Prompt assessment is needed for a persistent hard area, a pocket-like swelling, nipple discharge that is bloody or unusual, or mastitis that occurs without breastfeeding. Emergency care is appropriate for severe weakness, confusion or breathing difficulty.

Does this look like inflammation, infection or an abscess? Should I continue feeding from the affected breast? Could latch, feeding frequency or pressure be contributing? Which pain relief is compatible with breastfeeding, and when should I return if symptoms persist?