Most lumps that appear while breastfeeding are caused by normal lactating tissue, blocked ducts, galactoceles, or mastitis. They are rarely cancer. But because lactating breasts are dense and tender, distinguishing one from another can be hard — and a calm clinical assessment quickly tells you which is which.
Blocked duct
A firm, tender lump in one breast, usually after a missed feed, tight bra, or skipped breast pump session. The skin may be slightly red. No fever.
Treatment: feed or pump frequently from the affected side, warm compress before feeds, gentle massage from the lump towards the nipple, varied feeding positions, well-fitted nursing bra. Most resolve within 24–48 hours.
Galactocele
A smooth, mobile, painless cyst filled with milk. Often noticed weeks to months after starting weaning. Diagnosis is by ultrasound. Small galactoceles often resolve. Large or uncomfortable ones can be aspirated under ultrasound guidance — a simple, painless office procedure.
Mastitis
Painful, red, hot, swollen segment of one breast with fever (>38°C), chills and flu-like symptoms. Caused by milk stasis ± bacterial infection.
Treatment: continue breastfeeding (it is safe and helpful), oral antibiotics for 7–10 days, paracetamol/ibuprofen, frequent emptying of the breast. Most improve in 48–72 hours. Always review at 48 hours — if not improving, ultrasound to rule out abscess.
Breast abscess
Untreated or recurrent mastitis may form an abscess — a pocket of pus. Ultrasound is diagnostic. First-line treatment is needle aspiration under ultrasound guidance (often repeated 2–3 times), with antibiotic cover. Surgical drainage is reserved for very large or multi-loculated abscesses.
When to worry
Book a consultation if you have:
- •A lump that persists more than 2 weeks despite emptying the breast
- •A hard, fixed lump
- •Skin dimpling or nipple inversion
- •Blood-stained discharge
- •Family history of breast cancer These features are unusual in lactational lumps and warrant ultrasound — and core-needle biopsy if needed.
Pregnancy-associated breast cancer
Rare (about 1 in 3000 pregnancies) but important. Any persistent, non-tender lump in a pregnant or breastfeeding woman should be investigated. Ultrasound and core biopsy are safe during pregnancy and lactation.