Mastitis: symptoms, treatment, causes and what to do while breastfeeding

The NHS says mastitis usually affects only one breast, and symptoms often come on quickly. They include a swollen area on your breast that may feel hot and painful to touch (the area may become red, but this can be harder to see on black or brown skin), a wedge-shaped breast lump or a hard area, a burning pain in your breast that might be constant or only when you breastfeed, and nipple discharge, which may be white or contain streaks of blood.

You may also get flu-like symptoms, such as aches, a high temperature (or feeling hot, cold or shivery) and tiredness. The Breastfeeding Network says this feeling can sometimes start very suddenly and get worse very quickly, and notes that you may not have all of the signs. On darker skin tones there might be a darkening of the skin, and there could be no visible change in skin colour at all.

The NHS says mastitis does not usually need medical treatment, and gives a list of things you can do to ease it. A GP will usually prescribe antibiotics if you have mastitis and your symptoms are not getting better. The Breastfeeding Network says harmful bacteria are not always present, and antibiotics may not be needed if self-help measures are started promptly.

If you do need antibiotics, the Breastfeeding Network says most antibiotics can be safely taken while breastfeeding, and that it is important to finish the whole course. The NHS says a very small amount of the antibiotic may go into your breast milk; there is no risk to your baby, but it might make them irritable and restless.

The NHS lists the following, and the Breastfeeding Network gives similar advice.

• Do continue breastfeeding and make sure your baby is positioned and attached properly.

• Do apply a cold compress to the affected breast for 10 minutes every hour, and take paracetamol or ibuprofen for pain or a high temperature.

• Do rest, and wear a comfortable and supportive bra.

• Do not wear tight-fitting clothing or bras until you feel better.

• Do not take aspirin.

• Do not express more milk than your baby needs, and do not apply firm pressure to the breast; any pressure should be gentle.

• Do not stop breastfeeding suddenly.

• Do not apply oils, soaks or creams to your breast.

The NHS says mastitis is common in breastfeeding women because it can be caused by a build-up of milk. The Breastfeeding Network explains that you may get mastitis when milk leaks into breast tissue from a blocked duct, and that the body reacts in the same way as to an infection by increasing blood supply, producing inflammation.

It lists factors that make it more likely: difficulty attaching the baby to the breast, pressure from tight clothing or a finger pressing into the breast during feeds, engorgement or a blocked duct, sudden changes in how often the baby feeds, and injuries such as bumps or knocks from toddlers. It advises avoiding suddenly going longer between feeds, and cutting down gradually if you are reducing breastfeeding.

The NHS says women who are not breastfeeding can also get mastitis, as can men, and lists smoking, damage to the nipple such as a piercing or a skin condition such as eczema, having a breast implant, a weakened immune system due to a health condition such as diabetes, and shaving or plucking hairs around the nipples.

The NHS says to see a GP if your symptoms do not get better 12 to 24 hours after treating it at home, if your symptoms do not get better 48 hours after taking antibiotics, or if you get mastitis and you are not breastfeeding.

The Breastfeeding Network says to contact your GP if the area becomes round and swollen or the redness or colour change pattern changes, because mastitis can develop into an abscess (a painful collection of pus). If mastitis comes back after a full course of antibiotics, or is unusually severe, it says a sample of milk may be sent for bacteria tests.

The Breastfeeding Network says that if you feel seriously unwell, dizzy, confused, or develop nausea, vomiting, diarrhoea or slurred speech along with the symptoms of mastitis, you need to seek urgent medical attention, because these can be signs of mastitis developing into sepsis, which is a medical emergency needing urgent hospital admission and IV antibiotics. Very rarely mastitis can develop into a more serious condition.

If you are worried, use NHS 111, or call 999 in an emergency.

The NHS says if you are breastfeeding and keep getting mastitis, it might be due to problems with positioning and attaching, and it is important to ask for help from a midwife, health visitor or a breastfeeding specialist as soon as possible. It gives the National Breastfeeding Helpline as a source of help, open 24 hours a day.

The Breastfeeding Network lists signs that a baby is well attached: the chin firmly touching the breast, a wide open mouth, a large mouthful of breast, no pain beyond the first few sucks, rounded cheeks and rhythmic sucks and swallows.

On the NHS, midwives, health visitors and breastfeeding specialists give feeding support, and a GP can prescribe antibiotics and send a milk sample if needed. The National Breastfeeding Helpline offers support at any time of the day.

Private lactation consultants and GP services are available. Because the evidence on self-help and the guidance on safe medicines are the same, ask a private provider whether they follow NHS guidance on antibiotics and on avoiding firm massage.