A breast abscess is a painful, pus-filled pocket that forms in breast tissue, usually as a complication of a breast infection (mastitis) that wasn’t treated quickly enough. It causes a firm, swollen lump that feels warm and tender, often alongside fever and general malaise. Breast abscesses can develop in anyone, though they’re most common in breastfeeding women.
How a Breast Abscess Forms
Most breast abscesses start as mastitis, an infection of the breast tissue. In breastfeeding women, the process typically begins when cracked or sore nipples allow bacteria from the baby’s mouth to enter the milk ducts. Those bacteria multiply rapidly in the milk, triggering inflammation. A blocked milk duct can also set the stage for infection by trapping milk and creating a breeding ground for bacteria.
If the infection isn’t cleared with antibiotics or improved breastfeeding technique, the body walls off the infected area with a capsule of inflamed tissue. Pus, made up of dead white blood cells, bacteria, and fluid, collects inside that capsule. At that point, antibiotics alone can no longer reach the core of the infection, and the pus needs to be physically drained.
Lactational vs. Non-Lactational Abscesses
Lactational abscesses occur during breastfeeding and account for the majority of cases. Non-lactational abscesses are less common but follow a similar process. They tend to develop in women who have had breast surgery followed by radiation, women with diabetes, or those with weakened immune systems.
The link with diabetes is especially strong. A study in The American Journal of the Medical Sciences found that among non-lactating women with breast abscesses, 72% had diabetes. The odds of having diabetes were roughly 14 times higher in non-lactating women with a breast abscess compared to those without one. Women with diabetes also experienced longer hospital stays and a more severe course of illness. In fact, researchers suggested breast abscesses should be considered a “typical” infection associated with diabetes in this group. Seven out of 27 women in the study who did not have diabetes at the time of their abscess went on to develop it within five years.
Symptoms to Recognize
The hallmark signs of a breast abscess include:
- A lump or swelling in the breast that feels firm or fluctuant (slightly squishy, like a water balloon)
- Pain, warmth, and redness over the affected area (redness can be harder to see on darker skin tones, so warmth and pain are more reliable indicators)
- Fever or chills
- Feeling generally unwell, similar to having the flu
An abscess feels different from the diffuse soreness of mastitis. The pain tends to concentrate in one spot, and you can often feel a distinct lump that grows more tender over days. If you’ve been treating mastitis with antibiotics for 48 hours and symptoms aren’t improving, an abscess may have formed.
How Abscesses Are Treated
The core treatment is drainage: the pus has to come out. There are two main approaches, and the choice depends on the size of the abscess and how your doctor assesses it.
Needle Aspiration
A doctor inserts a needle into the abscess, often guided by ultrasound, and withdraws the pus with a syringe. This is less invasive and leaves no scar. However, it has a lower success rate. A randomized trial published in Annals of Emergency Medicine found that ultrasound-guided needle aspiration resolved skin abscesses only about 26% of the time, compared to 80% for surgical drainage. Multiple aspiration sessions are sometimes needed, and smaller abscesses respond better than larger ones.
Incision and Drainage
A small cut is made in the skin over the abscess to let the pus drain out. Sometimes a small tube or strip of gauze is left inside the cavity temporarily so fluid can continue draining rather than re-accumulating. This approach has a higher success rate but leaves a small wound that needs daily care as it heals from the inside out.
Abscesses caused by MRSA, a drug-resistant type of staph bacteria, are harder to treat with either method. In the same trial, success rates dropped to 8% for needle aspiration and 61% for incision and drainage when MRSA was the culprit. If an initial treatment doesn’t work or if there’s concern about resistant bacteria, your doctor may send a sample of the drained pus to a lab to identify exactly what’s growing.
Antibiotics are prescribed alongside drainage, typically for 10 to 14 days, though a shorter course may be appropriate if the surrounding redness and swelling resolve quickly.
Recovery and Wound Care
After drainage, the wound is left open intentionally so any remaining infected fluid can escape. You’ll likely need to change gauze packing or dressings at home, following your doctor’s specific instructions for keeping the area clean. The cavity gradually fills in with healthy tissue from the bottom up over the course of one to several weeks, depending on the size of the abscess.
Ice or a cold pack applied for 10 to 15 minutes at a time helps with pain and swelling in the days after treatment. If you’re breastfeeding, apply cold packs between feedings rather than right before nursing. Over-the-counter pain relievers are generally sufficient for managing discomfort, though your doctor may prescribe something stronger for the first few days.
Signs that recovery isn’t going as expected include increasing redness spreading outward from the wound, new or worsening fever, or the lump returning. These can indicate that the abscess has re-formed or that infection is spreading into surrounding tissue.
Breastfeeding During Treatment
You can continue breastfeeding from the affected breast, even before the abscess is drained. Both breast milk and breastfeeding remain safe during mastitis, abscess treatment, and while taking antibiotics. The Academy of Breastfeeding Medicine recommends feeding at the breast or hand expressing rather than using a pump, since pumping can further irritate inflamed or damaged tissue. You should also avoid increasing feeding frequency or expressing extra milk on the affected side, as overstimulation can worsen the problem.
Some women find nursing on the affected side too painful, especially if the abscess is near the nipple or the drainage site. In that case, feeding from the unaffected side while the other heals is reasonable. Milk supply on the affected side typically recovers once the infection clears.
Who Is Most at Risk
Breastfeeding women in the first few weeks postpartum face the highest risk, particularly if they have cracked nipples, difficulty with latch, or incomplete breast emptying. First-time mothers are more commonly affected, likely because they’re still establishing breastfeeding technique.
Outside of breastfeeding, the strongest risk factor is diabetes. Women with a history of breast surgery and radiation are also more susceptible, as scar tissue can block normal drainage pathways in the breast. A suppressed immune system from any cause, whether medication, chronic illness, or other factors, raises vulnerability to infections that can progress to abscess formation.
Recurrence is a real concern, particularly for non-lactational abscesses. Women with diabetes tend to experience more complicated and prolonged courses, and the abscess can return in the same location if the underlying conditions haven’t changed. Completing the full course of antibiotics and attending follow-up appointments reduces, but doesn’t eliminate, this risk.