Mastitis Symptoms and Treatment

Mastitis Symptoms and Treatment

4 min readUpdated November 27, 2025

Key Takeaways

  • Mastitis is a painful inflammation of breast tissue, often linked to a blocked milk duct or infection. It usually affects one breast and comes on suddenly.

  • Key symptoms include: a hard, tender lump or red, swollen area; burning pain (especially during feeds); warmth, fever, chills and flu-like symptoms.

  • Common causes include: poor latch, missed feeds, tight bras, cracked nipples or lowered immunity due to stress or illness.

  • Keep breastfeeding or expressing to help clear the blockage. Start on the affected side, rest, stay hydrated, and use warm compresses and gentle massage.

  • Seek medical advice if symptoms don’t improve within 24 hours. Antibiotics safe for breastfeeding may be prescribed if an infection is present.

  • If you develop symptoms like dizziness, confusion or vomiting, seek urgent care – these may be signs of sepsis.

  • Prevention tips. Ensure a good latch, feed on demand, wear non-restrictive clothing and wean gradually.

  • Mastitis doesn’t mean you must stop breastfeeding. In fact, continued feeding often helps relieve symptoms and is safe for your baby.

Mastitis is an inflammation of breast tissue that may result from a blocked milk duct, a bacterial infection or a combination of the two, causing hotness, tenderness and pain in one (or more rarely both) of your breasts.
Having mastitis can be very frustrating, especially if you are breastfeeding, but it is treatable if you recognise the early signs and take steps to alleviate it.
Read on to find out what causes mastitis, and how you can prevent mastitis or treat the symptoms so you can get back to breastfeeding your little one without discomfort as soon as possible.

What Is Mastitis?

Mastitis is an inflammation of the breast that can sometimes be caused by a build-up of milk causing a milk duct in your breast to get blocked.
When this happens, your body reacts in the same way as it would to an infection: by sending more blood to the affected area. This is what causes the redness, tenderness and swelling associated with mastitis.
With mastitis a hard lump can form, and your breast can become tender and sore. If the clogged duct isn’t cleared quickly, a breast infection may set in.
Mastitis is most common in breastfeeding mums and mums who are expressing their milk, but it can also happen in people who aren’t producing breast milk — sometimes even men get it.
The mastitis that’s related to breastfeeding or expressing milk is referred to as lactational mastitis. This article will focus on this kind of mastitis.

Mastitis Symptoms

You may be wondering how to tell the difference between mastitis and the normal tenderness you might feel when you first start breastfeeding.
The symptoms of mastitis often appear suddenly, and usually affect only one breast. These symptoms can include
  • a wedge-shaped lump or hard patch in one of your breasts
  • a red, swollen area on the breast that may hurt
  • the breast feels warm to the touch
  • a burning pain that’s either constant or occurs just when you’re breastfeeding
  • flu-like symptoms such as fever, chills, aches and feeling tired.

What Causes Mastitis

Lactational mastitis – that is, mastitis related to breastfeeding or expressing milk – is most likely to occur if your breasts don’t empty completely during feeds. This can cause milk to build up and become trapped in the milk ducts.
Mastitis can also result from a bacterial infection, or an infection may develop as a result of mastitis that starts out with a blocked milk duct. Here are some things that might increase your risk of developing mastitis:
  • Poor latch. If your baby doesn’t latch properly onto your nipple when feeding, your breast might not empty completely during feeds. Ask your health visitor or a lactation consultant for advice on proper latch.
  • Missed or infrequent feeds. Your breasts increase the supply of milk to meet demand. If you miss out a feed or breastfeed at irregular intervals your breasts may not drain completely. This could make a blocked milk duct more likely, possibly leading to mastitis.
  • Favouring one breast over the other. If you feed your baby more from one breast than the other, the underused breast may not be cleared, increasing the risk of a blockage.
  • Tight clothing or pressure on your breasts. Wearing a tight bra or putting pressure on your breast while feeding (for example by pushing down on it with a finger) can restrict the flow of milk.
  • An injured milk duct or gland. Accidental bumps or knocks to your breast can cause an injury that might affect milk flow, preventing the duct from fully clearing.
  • A cracked, damaged nipple. Cracked or sore nipples can make you more susceptible to a bacterial infection in the breast. Skin conditions like eczema can also increase the risk of infection.
  • Shaving or plucking the hairs around your nipples. This can damage the skin, making it easier for bacteria to find a foothold.
  • A weakened immune system. Stress or poor nutrition, as well as some chronic diseases or some medications, can suppress your immune system and make you more susceptible to the infections that sometimes lead to mastitis.
  • Smoking. Tobacco contains toxins that can increase the risk of mastitis.

Treatment for Mastitis

Although mastitis can be uncomfortable or painful, the good news is it’s usually easy to treat and soon clears up, especially if you catch it early.
If the mastitis doesn’t start clearing up within 24 hours with the home remedies described below, your doctor may prescribe antibiotics that are safe for your baby too, should you be breastfeeding your little one.

Self-help Methods to Relieve Mastitis Symptoms

If you start experiencing the early signs of mastitis, you might try some of these self-help methods to ease the discomfort:
  • Keep on breastfeeding or expressing your milk, and don’t reduce the number or length of feeds, as this can cause your milk supply to drop, prolonging recovery. Read more about how to increase your breastmilk supply.
  • Drink plenty of fluids and get as much rest as you can
  • Fully drain the milk from each breast at each feed. Feeding from the affected breast first helps it empty completely as your baby won’t be starting to feel full yet.
  • If breastfeeding is too painful, try hand-expressing or using a breast pump to keep the milk flowing
  • Apply wet or dry heat to the affected breast just before breastfeeding or expressing, or simply to ease the pain. A warm flannel can work well, or you could take a warm shower.
  • Gently massage the affected area of your breast, as long as it’s not too painful
  • Go braless and wear loose-fitting clothing to lessen the pressure on your breasts.

Antibiotics

If the symptoms of mastitis don’t start easing up within 24 hours, or if there’s any other reason to suspect a bacterial infection in your breast, your doctor will likely prescribe a course of antibiotics.
Always follow your doctor’s instructions on how to take any medicines that are prescribed for you. If the symptoms don’t start getting better within 48 hours after starting to take antibiotics, it’s a good idea to go back to your doctor.

When to See the Doctor

Early treatment of mastitis is important. See your doctor if the symptoms get worse or don’t clear up within 24 hours despite trying some of the self-help methods mentioned above. If it’s left untreated, mastitis can develop into a painful breast abscess, which may need hospital treatment.
If you are considering taking a painkiller, always ask your doctor or health visitor first which pain relief medication may be safe to take while breastfeeding.
Check in with your doctor straight away if you have any other symptoms – such as a fever, aches or chills, or if you’re at all concerned about what you’re experiencing.
In very rare cases, mastitis can develop into sepsis, which needs urgent medical attention. Call an ambulance or go to your local A&E unit if you have mastitis and experience dizziness, slurred speech, confusion, nausea, vomiting or diarrhoea.

Can You Keep on Breastfeeding With Mastitis?

Yes you can. In fact, sticking to your regular feeding routine is usually the best thing you can do if you have mastitis. Keeping up a steady flow of milk helps to clear any blockages in the milk ducts.
That’s not all: If you stop breastfeeding, it could actually make the symptoms worse as your breasts continue to produce more milk that has nowhere to go.
Rarely, you might find that the mastitis makes feeding from the affected breast too painful. If that’s the case, it might help to gently express a little milk from the affected breast and either store it for later or feed it to your baby straight away using a bottle.
After relieving some of the pressure in this way, you might be able to finish nursing on the affected breast without too much discomfort.

Does Mastitis Affect Breast Milk?

Breastfeeding while you have mastitis won’t harm your baby. Even if you have an infection, it won’t be passed on. If you’re taking antibiotics for your mastitis this doesn’t present a risk for your little one either, as long as your doctor knows that you’re breastfeeding you’ll be prescribed a medicine that is safe to take.
Keep in mind, a tiny amount of the antibiotics may be passed into your breast milk and this could make your little one a little irritable, and his or her poo may be a bit runnier while you’re taking them.

How to Prevent Mastitis

Here are some things you might like to try to help prevent mastitis in the first place:
  • Varying your breastfeeding positions may help completely empty each breast and help prevent a blockage
  • Make sure your baby is properly latched on to your nipple during feeds
  • Feed your baby for as long as he or she will eat
  • Feed your little one whenever he or she is hungry, and try not to leave too much time between feeds
  • Apply a warm, wet flannel to your breasts or take a warm shower before breastfeeding, as this can help get the milk flowing freely — even if you don’t have mastitis
  • Wear loose clothing and a comfortable bra that doesn’t constrict your breasts
  • Eventually, when you decide it’s time to stop breastfeeding and wean your baby, it’s best to phase out breastfeeding gradually.

FREQUENTLY ASKED QUESTIONS

Mastitis usually clears up quickly, as long as you recognise the early signs and start treatment straight away. If antibiotics are needed, the symptoms should start clearing within 48 hours.

Breastfeeding or expressing with mastitis can be difficult and frustrating. Try to be patient and gentle with yourself during this time.
Keep in mind that continuing to breastfeed will speed up recovery and help stop the mastitis from worsening, and you’ll keep giving your baby the benefits of your breast milk, such as extra protection from infections and diseases.
As long as you recognise the early signs of mastitis and see your doctor as soon as possible if necessary, it won't be long until you're back to enjoying this bonding time with your baby.

How we wrote this article
The information in this article is based on the expert advice found in trusted medical and government sources, such as the National Health Service (NHS). The content on this page should not replace professional medical advice. Always consult medical professionals for full diagnosis and treatment.

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