Mastitis is an infection in the tissue of one or both of the mammary glands inside the breasts. It usually affects people who are producing milk and nursing.

There is often a hard, sore spot inside the breast. This can result from a blocked milk duct or because bacteria enter the breast through a break in the skin.

Mastitis that occurs during breast-feeding is also known as lactation mastitis. It is thought to affect around 10 percent of all breast-feeding mothers. However, study results vary significantly, from a very small percentage of cases up to 33 percent.

It often develops during the first 3 months after giving birth, but it can occur up to 2 years later.

Some mothers mistakenly wean their infants when they develop mastitis. In most cases, breast-feeding should continue during mastitis. Mastitis usually only affects one breast.

Sometimes, it can affect women who are not lactating, but it is uncommon. In very rare cases, it can affect men.

Fast facts on mastitis

  • Mastitis rarely affects more than one breast at a time.
  • In very rare cases, mastitis can affect males.
  • Mastitis often starts with a blocked milk duct.
  • Symptoms can include chills, fatigue, and a swollen breast.
Was this helpful?

Signs or symptoms may develop rapidly. They can include:

  • an area of the breast becoming red and swollen
  • the affected area of the breast hurting when touched
  • the affected area feeling hot when touched
  • a burning sensation in the breast that may always be there or only when breast-feeding
  • flu-like symptoms

The following symptoms may be present:

  • anxiety and feeling stressed
  • chills and shivering
  • elevated body temperature
  • fatigue
  • general aches and pains
  • a feeling of malaise
Share on Pinterest
Mastitis occurs in around 10 percent of breast-feeding mothers.

The first line of treatment is self-help remedies, such as ensuring that the breast is drained properly during feeds.

A doctor may prescribe antibiotics to treat the infection. They will also recommend techniques to treat the blocked duct, if this is the cause.

Some studies suggest that antibiotics do not help and may not be appropriate during breast-feeding. Non-medicinal remedies should be tried first.

If complications occur, and the condition is progressing quickly and looks likely to become more serious, hospitalization and antibiotic treatment may be recommended.

Ask the doctor about treating symptoms of pain and fever with acetaminophen, or Tylenol.

If the mastitis does not get better, the individual should see a doctor again.

Mastitis when breast-feeding usually results from a blocked or plugged duct. The blockage causes milk stasis, when the milk that is produced does not come out during feeding and remains in the breast.

This can happen if the infant:

  • does not attach to the breast properly
  • has difficulty sucking the milk out of the breast
  • breast-feeds infrequently

Milk ducts can also become blocked because of pressure on the breast caused by tight clothing, for example.

Often, mothers will place a finger on the same spot every day to move the breast out of the way of the baby’s nose. This later becomes a plugged duct.

Anything that stops the milk from being properly expressed will usually result in milk stasis, and this often leads to milk duct blockages.

Bacteria do not generally thrive in fresh human milk. However, if the milk ducts are blocked, and the milk stagnates, infection is more likely.

Bacteria on the surface of the skin may enter the breast through small cracks or breaks.

Mastitis when not breast-feeding

Women who are not lactating, in other words, not producing milk and not breast-feeding, may develop mastitis.

This is not common and is referred to as periductal mastitis. Those who do develop non-lactating infectious mastitis tend to be regular smokers and in their late 20s to early 30s.

Experts believe that smoking may damage the milk ducts, making these more susceptible to infection.

Mastitis after nipple piercing

If nipple piercing is done at non-professional, unregistered piercing studios, this may increase the risk of mastitis.

The following self-care techniques can often resolve a blocked duct during breast-feeding:

  • Drink plenty of liquids and get enough rest.
  • Breast-feed frequently or express the milk if feeding is not possible.
  • Start a feed with the affected breast, to ensure it is drained more regularly.
  • After a feed, gently express any leftover milk.
  • Check with a health professional if the baby is attaching to the breast properly.
  • Try different feeding positions, to find the one that most effectively drains the breast.
  • Change positions often.
  • Warm the breast with a heated compress before a feed, as this can sometimes make it easier for the baby to get the milk out.
  • Apply cool compresses after feeding to soothe discomfort, for example, frozen bags of peas.
  • Use stroking techniques to help with milk flow, and massage the plugged duct during feeds.
  • Wear loose-fitting clothes.
  • Point the baby’s chin toward the plugged duct to facilitate the best drainage.
  • Place a cloth soaked with warm water over the breast to relieve pain.

If the problems persist, a range of support groups can help. They offer advice from certified lactation consultants. The United States Lactation Consultant Association (USLCA) can help.

La Leche League local meetings offer a chance to meet with other mothers.

Watching for plugged ducts in the future is important after healing, because plugged ducts and mastitis tend to re-occur.

Steps can be taken to prevent mastitis from developing when a plugged duct is felt.

  • Breast-feed frequently, especially when the breasts are full.
  • If possible, use only breast-feeding to nourish the infant for about 6 months.
  • Find out early if the infant is attaching correctly.
  • Do not detach the infant during feeding, but wait for them to relax and let go.
  • Avoid tight bras and other clothing.
  • Vary breast-feeding positions.
  • When it is time to wean, cut down gradually on feeds, not suddenly.
  • Check every day in the shower for any lumps developing behind the nipples.
  • Stay in a hot shower and let it run across the affected breast.
  • Apply heat before feeds and massage the duct.
  • Apply gentle pressure to the breast if rubbing the skin is painful.
  • Pump after feeds to reduce any engorgement until the mastitis has healed.
  • If a blister appears, as a small white dot on the nipple, apply heat and try to gently scratch that nipple pore open.
  • Talk to a healthcare provider about a lecithin supplement, as this may prevent re-occurrence.

When the duct releases, the milk may come out in a rush, but relief will be immediate. If a duct has been plugged for a while, the milk may come out thicker, more like a piece of cheese.

The milk itself will not be contaminated. It is not a good idea to quit breast-feeding when there is a blocked duct, as this can lead to engorgement as well as mastitis.

Rest is important because it helps improve the immune function, so that it can better fight any budding infection.

It is important to discuss any breast-feeding concerns with a health professional as soon as possible, to prevent problems developing.

Share on Pinterest
A doctor will diagnose mastitis upon physical examination.

Mastitis is fairly easy to diagnose. A doctor will perform a physical examination and ask about symptoms.

When symptoms are severe, or if the woman does not respond to treatment, the doctor may take a small sample of breast milk for testing.

This will:

  • determine whether there is a bacterial infection
  • identify the type of bacteria to help the doctor select the best treatment

If a breast-feeding problem is suspected as the cause, the woman may be asked to demonstrate how she breast-feeds.

It is important for the mother not to feel she is being blamed or judged. Breast-feeding often requires practice to perfect.

Inflammatory breast cancer, a rare form of breast cancer, can also have similar symptoms of redness and swelling. In some rare cases, a biopsy may be taken to rule out breast cancer.

Untreated mastitis can sometimes lead to complications.

  • Recurrence: If mastitis has happened once, it is more likely to happen again. Recurrence often results from late or inadequate treatment.
  • Abscess: Without proper treatment, a collection of pus, or abscess, can develop in the breast. This usually needs surgical draining.
  • Septicemia or sepsis: These are life-threatening conditions that can result if an infection is not treated.

Pain, fever, inflammation, and any persistent difficulty with breast-feeding should be discussed with a doctor.