Mastitis
Also known as: Breast inflammation, Lactational mastitis
Mastitis is inflammation of breast tissue that may or may not involve infection. It is most common in the first weeks of breastfeeding, when milk ducts become blocked or the breast is engorged, and bacteria from the baby's mouth or the skin can enter through cracked nipples. The affected area becomes hot, red, swollen, and painful, and many people feel suddenly unwell with flu-like aches and fever. Mastitis can also occur in people who are not breastfeeding, including men, though this is less common. Prompt treatment, including continuing to drain the breast, usually leads to rapid recovery, and most people can carry on breastfeeding.
At a Glance
- Common symptoms
- A hot, tender, red, or swollen area of the breast, sometimes wedge-shaped, Breast pain or a burning sensation, especially while feeding, A firm lump or thickened area
- Main treatments
- Continuing to breastfeed or express frequently from the affected breast to keep milk flowing, Antibiotics when infection is likely or symptoms are not improving within about 24 hours, Pain relief with ibuprofen or paracetamol (acetaminophen), both compatible with breastfeeding
- Category
- Reproductive · Common among breastfeeding women, especially in the early weeks; less common otherwise
- See a doctor if
- Symptoms have not improved within 24 hours of frequent feeding and self-care
Symptoms
Causes
- Milk stasis from infrequent or incomplete emptying of the breast
- Blocked milk ducts
- Bacteria (often Staphylococcus aureus) entering through cracked or damaged nipples
- Pressure on the breast from tight bras or sleeping position
- In non-breastfeeding people: duct ectasia, smoking-related inflammation, or skin infection
Risk Factors
- Breastfeeding, particularly in the first six weeks
- Cracked or sore nipples
- Poor latch or infrequent, rushed feeds
- Previous episode of mastitis
- Sudden changes in feeding pattern (such as a baby sleeping longer)
- Smoking, in non-lactational cases
Diagnosis
- Clinical examination of the breast and review of feeding history
- Culture of breast milk if infection is severe, recurrent, or not improving
- Ultrasound if an abscess is suspected
- Further investigation of persistent redness or a mass that does not resolve, to exclude rare inflammatory breast cancer
Treatment
- Continuing to breastfeed or express frequently from the affected breast to keep milk flowing
- Antibiotics when infection is likely or symptoms are not improving within about 24 hours
- Pain relief with ibuprofen or paracetamol (acetaminophen), both compatible with breastfeeding
- Needle aspiration or drainage if an abscess has formed
- Supportive: rest, fluids, and help from a lactation consultant to improve latch and positioning
- Supportive: cold packs between feeds to reduce swelling; gentle rather than deep massage, as aggressive massage can worsen inflammation
Prevention
- Feed or express frequently and avoid long gaps between feeds
- Make sure the baby latches well and empties the breast
- Vary feeding positions and avoid pressure on the breast from tight clothing
- Care for cracked nipples promptly
- Wean gradually rather than suddenly
When to See a Doctor
- Symptoms have not improved within 24 hours of frequent feeding and self-care
- Fever over 38.5°C (101.3°F) or feeling very unwell
- A hard, very painful lump that may be an abscess
- Pus or blood in the milk
- Redness or a lump that persists after the infection has cleared
Frequently Asked Questions
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