Breast Infection: Causes, Symptoms, and Treatment
Medically reviewed by Sumiran Racherla, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Breast Infection?
A primary care doctor, an obstetrician (pregnancy and childbirth doctor), or a midwife usually treats a breast infection. A breast surgeon may help if an abscess forms. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is breast infection?
A breast infection (mastitis) is an infection in the tissue of the breast. It is usually caused by Staphylococcus aureus, a common bacteria found on normal skin. The bacteria enter through a break or crack in the skin, usually on the nipple. The infection develops in the fatty tissue of the breast and causes swelling. This swelling pushes on the milk ducts, which causes pain and lumps in the infected breast.
Breast infections usually occur in women who are breastfeeding. Infection or inflammation that is not related to breastfeeding might be due to a rare form of breast cancer, so any breast change needs a doctor's check.
Symptoms
Symptoms may include:
- Breast enlargement or fullness on one side only.
- Breast pain, and swelling, tenderness, and warmth in the breast tissue.
- Skin redness, most often in a wedge shape.
- A breast lump, or nipple discharge that may contain pus.
- Fever and flu-like symptoms, including nausea, vomiting, and aching muscles.
- Tender or enlarged lymph nodes in the armpit on the same side.
Causes and who gets it
Breastfeeding mothers get most breast infections. Milk that stays in the breast raises the risk, so feeding often and pumping help. Cracked or sore nipples let bacteria in. A plugged milk duct, a duct blocked by thickened milk, can also lead to infection. This can happen if the baby does not feed well, if feedings are skipped, or if the bra is too tight.
Good breastfeeding technique with a proper latch lowers the risk. Wearing a comfortable bra between feedings also helps.
How doctors diagnose it
A health care provider does a physical exam to check the breast and look for an abscess, a swollen, pus-filled lump. Sometimes an ultrasound, a scan that uses sound waves, is done to check for an abscess. For infections that keep returning, fluid from the nipple may be cultured, meaning it is tested to identify the bacteria. In women who are not breastfeeding, tests may include a mammogram, breast ultrasound, breast MRI, or a breast biopsy.
Treatment
Antibiotics are very effective in treating a breast infection. If you take antibiotics, continue to breastfeed or pump to relieve breast swelling from milk production. Breast milk is safe for your baby, even when you have a breast infection.
Self-care may include applying moist heat to the infected breast for 15 to 20 minutes four times a day. Pain relievers may also help. Rest, good nutrition, and drinking enough fluids support recovery. Continuing to nurse from the infected breast helps healing and prevents further engorgement.
If an abscess forms, it needs to be drained, either as an office procedure or with surgery. Doctors may first try needle aspiration under ultrasound guidance, along with antibiotics.
When to see a doctor
Contact a doctor right away if any part of your breast becomes reddened, tender, swollen, or hot. Also contact a doctor if you are breastfeeding and develop a high fever, or if the lymph nodes in your armpit become tender or swollen. A breast infection needs prompt treatment so it does not progress to an abscess.
Call 911 or go to the emergency room if you have a fever along with confusion or trouble waking up, trouble breathing, fainting, or a very weak and dizzy feeling. These can mean the infection has spread through the body.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Either can examine a painful or red breast, start treatment, and arrange an ultrasound when needed. They can follow up closely during recovery and refer you to a breast specialist if the infection keeps coming back.
Common questions
Can I keep breastfeeding with mastitis?
Yes, in most cases. Continuing to nurse from the infected breast helps healing and prevents engorgement. Breast milk is safe for your baby even when you have a breast infection. If nursing is too painful, you can pump or express milk instead.
How is a breast abscess treated?
It needs to be drained, either as an office procedure or with surgery. An abscess is a swollen, pus-filled lump. Doctors often first try needle aspiration, using a needle to withdraw the pus, with ultrasound guidance and antibiotics.
Can mastitis be prevented?
Some steps may help. Care for your nipples to prevent irritation and cracking. Feed often and pump milk to prevent engorgement. Use proper breastfeeding technique with a good latch. Wean slowly over several weeks instead of stopping quickly. Treat any infection early before it becomes an abscess.
Does mastitis mean cancer?
No, breast infections are usually caused by bacteria and clear quickly with antibiotics. But breast infection or inflammation that is not related to breastfeeding might be due to a rare form of breast cancer, so any breast change should be checked by a doctor.
Sources
- MedlinePlus - Breast infection
- MedlinePlus - Overcoming breastfeeding problems
- CDC - MRSA and Breastfeeding
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
