What should you know about interstitial mastitis?

Interstitial mastitis is inflammation in breast tissue that may cause tenderness, swelling, warmth or pain, especially during breastfeeding. It can affect one area or a wider part of the breast, and symptoms may occur with or without milk-flow problems.

Inflammation may follow milk stasis, pressure on the breast, a damaged nipple or changes in feeding patterns. The breast may feel firm, sore or hot, while the skin can look flushed. Fever, chills or feeling generally unwell can suggest a more active infection and need medical assessment. A breast lump that persists after feeding or treatment should also be examined, because inflammation is not the only possible cause.

Continue breastfeeding or expressing if it is comfortable, and avoid forceful massage or trying to empty the breast aggressively. Rest, drink fluids and use a cool pack wrapped in cloth for short periods. Check positioning and attachment, since shallow attachment can injure the nipple and limit milk removal. A lactation consultation can help adjust feeding technique and relieve pressure. Breast Pain and Painful Breastfeeding provide more symptom-focused guidance.

Contact a clinician promptly if you have fever, chills, rapidly increasing redness, severe pain, pus, or feel faint or very unwell. Arrange an assessment if symptoms are not improving, recur, or a lump remains after inflammation settles. Urgent help is appropriate for confusion, breathing difficulty or marked weakness.

Could this be inflammation, infection or another breast problem? Do I need an examination, ultrasound or medicine? How should I feed or express while the breast heals? What changes should prompt a same-day review?