Acute and chronic mastitis: what to know

Acute mastitis often causes a rapidly developing area of breast pain, warmth, redness or swelling, sometimes with fever or flu-like symptoms. Chronic mastitis describes inflammation that lasts, returns or develops more gradually; infection is only one possible explanation.

During breastfeeding, milk stasis, nipple damage and bacterial infection can contribute to inflammation. Mastitis can also occur outside lactation. Persistent inflammation may be associated with a blocked duct, an abscess, skin disease or another breast condition, so examination matters when symptoms do not settle.

A clinician may assess the skin, nipple and deeper breast tissue. Ultrasound, a milk or fluid sample, or other breast imaging may be considered when there is a lump, a suspected collection of pus, an unusual presentation or repeated episodes.

If you are breastfeeding, continue comfortable milk removal by feeding or expressing without forceful massage or excessive pumping. A cold compress after feeds, supportive clothing, rest and a pain reliever that is suitable for you may ease discomfort. A lactation professional can check attachment, positioning and feeding patterns.

Arrange a clinical review if symptoms are marked, recurrent or not improving. Antibiotics help bacterial mastitis but do not treat every cause; take them only as prescribed and complete the advised course. An abscess may need drainage as well as medication.

Seek same-day medical advice for fever with worsening breast redness or pain, pus or bloody discharge, rapidly increasing swelling, or feeling very unwell. Urgent assessment is also appropriate for a soft or fluctuant swelling that may be an abscess.

Book a breast assessment for a lump, nipple change, skin dimpling, persistent one-sided redness, or symptoms that keep returning. These findings can have several causes and need direct examination rather than diagnosis from appearance alone.

You might ask whether the pattern suggests infection, milk stasis or another inflammatory condition; whether imaging or a sample is needed; how to manage feeding safely; and what change should prompt reassessment. Mention previous episodes, recent antibiotics, nipple damage, smoking, diabetes, breast procedures and whether you are lactating.