Mastitis: Symptoms, Treatment, and Prevention

Mastitis strikes many breastfeeding mothers without warning. You can go from feeling completely fine to having intense breast pain within a matter of hours.

The good news is that mastitis (breast inflammation) can be treated effectively at home in most cases. Here is what to look for, what you can do yourself, and when to contact a doctor.

Mastitis Symptoms

Mastitis usually develops in one breast at a time. Symptoms come on suddenly and can feel overwhelming. Many describe it as being "hit by a wall" — one moment everything is normal, the next you have chills and breast pain.

Local breast symptoms:

• Redness in a defined area, often wedge-shaped
• Warmth and swelling
• Hard, tense breast with lumps
• Intense tenderness and pain to the touch

General body symptoms:

• Fever above 38.5°C (101.3°F)
• Chills and feeling cold
• Muscle aches and general illness
• Fatigue and exhaustion

The symptoms can resemble influenza. If you are breastfeeding and suddenly feel ill with breast pain, mastitis is the most likely explanation.

Blocked Milk Duct vs. Mastitis

Many people confuse these two conditions, and that is understandable. A blocked milk duct can develop into mastitis if it does not resolve.

Blocked milk duct:

• One or more small, tender lumps in the breast
• Some redness around the lump
• Temperature usually below 38.5°C (101.3°F)
• You feel mostly well otherwise
• Usually resolves within 1–2 days

Mastitis:

• Larger red, hot area in the breast
• Temperature above 38.5°C (101.3°F)
• Chills and muscle aches
• You feel clearly unwell
• May require antibiotic treatment

A blocked duct is the milder version. If you treat it early with frequent feeding and cooling, you can often prevent it from developing into full mastitis. The transition between the two is gradual, so it is wise to take action as soon as you notice a lump.

Causes of Mastitis

Mastitis develops when milk production exceeds drainage. Milk that remains in the breast creates pressure and inflammation.

Common causes:

• Poor emptying — the baby has an incorrect latch or feeds too infrequently
• Irregular feeding — sudden changes in feeding rhythm, such as during travel or illness
• Pressure on the breast — a too-tight bra, a carrier that presses, or sleeping face-down
• Stress and exhaustion — a weakened immune system makes you more vulnerable
• Sore nipples — bacteria can enter through cracks in the skin
• Rapid weaning — stopping breastfeeding suddenly causes milk to build up

Your baby plays an important role. A good latch and a regular feeding rhythm are the best defenses against mastitis. Many people experience their first episode in the first 6 weeks after birth, when breastfeeding has not yet found its rhythm.

Wondering if your baby has the right latch? Check our guide to breastfeeding positions for tips on finding a position that ensures good drainage.

Treating Mastitis

The most important thing you can do is continue breastfeeding. The milk is safe for your baby even when you have inflammation. Stopping breastfeeding makes the situation worse because the breast fills further.

Step by Step: What to Do at Home

1. Continue feeding — start with the sore breast

Begin each feeding on the inflamed breast. The baby sucks most strongly at the start, which helps drainage. If you feed from both breasts, always start with the sore one.

2. Cool down between feedings

Place a cool compress on the sore area for 10–20 minutes between feedings. A frozen bag of peas wrapped in a cloth works well. Cold reduces swelling and pain.

3. Apply warmth before feeding

A warm cloth or a warm shower just before feeding can help the let-down reflex. Warmth widens the milk ducts and helps milk flow more easily. Apply warmth for 5–10 minutes, no longer.

4. Pain relief

Paracetamol (acetaminophen) and ibuprofen can be combined for better effect. Ibuprofen is especially useful because it also reduces inflammation. Both medications are safe during breastfeeding.

5. Rest as much as possible

Your body needs energy to fight the inflammation. Ask for help and prioritize rest. Lie down with your baby and let your partner or family handle everything else.

What to Avoid

• Massage and forceful manual draining of the breast
• Tight bras or clothing pressing against the breast
• Skipping feedings or increasing time between them
• Stopping breastfeeding abruptly

When Do You Need Antibiotics?

Not all mastitis requires antibiotics. Here is how to assess:

You likely do NOT need antibiotics if:

• Symptoms improve within 12–24 hours
• The fever comes down with paracetamol and ibuprofen
• The sore area in the breast is getting smaller
• You gradually feel better

You SHOULD contact a doctor if:

• No improvement after 24 hours of home treatment
• Fever above 38.5°C (101.3°F) that persists or rises
• Symptoms worsen — more redness, more pain, more swelling
• You feel significantly worse

For bacterial mastitis, a doctor will typically prescribe dicloxacillin 500 mg four times daily for 10 days. The dose may be increased for severe cases. If you are allergic to penicillin, alternatives include clindamycin or cephalexin. Always confirm antibiotic safety during breastfeeding with your doctor.

You can and should continue breastfeeding during antibiotic treatment. The medication passes into the milk in very small amounts that will not harm your baby. Your doctor can confirm that the antibiotic is safe during breastfeeding.

How to Prevent Mastitis

Many cases of mastitis can be prevented with a few simple habits. Prevention is fundamentally about two things: good breast drainage and a healthy immune system.

Breastfeeding technique and routine:

• Feed frequently and regularly — ideally 8–12 times per day for newborns
• Make sure the baby has a deep, correct latch
• Vary feeding positions so the breast empties evenly
• Let the baby finish one breast before switching

Clothing and comfort:

• Wear a supportive, but not tight, nursing bra
• Avoid clothing or carriers that press against the breast
• Be careful at night — avoid lying on the breast for extended periods

General health:

• Get enough rest — sleep deprivation weakens the immune system
• Eat a varied diet and drink enough fluids
• Treat sore nipples early to prevent bacteria from entering

Need tips for maintaining your milk supply? Read our guide on how to increase milk production.

Frequently Asked Questions

Is my milk safe for the baby when I have mastitis?

Yes. The milk is completely safe, even when you have fever and breast pain. Breast milk also contains antibodies that protect your baby. The milk may taste slightly saltier than usual, causing some babies to protest a little. Keep trying — emptying the breast is crucial to your recovery.

Can I take pain relief while breastfeeding?

Yes. Both paracetamol (acetaminophen) and ibuprofen are safe during breastfeeding and are recommended by the AAP and WHO. You can combine the two for better effect. Ibuprofen also helps with the underlying inflammation.

How long does mastitis take to clear up?

With non-bacterial mastitis, most people notice improvement within 12–24 hours of proper home treatment. Bacterial mastitis requiring antibiotics usually takes 2–3 days before you notice clear improvement. Always complete the full antibiotic course.

Can mastitis come back?

Unfortunately, yes. Some people experience recurrent episodes, especially if the underlying cause has not been resolved. Common causes of recurring mastitis include a poor latch, too-tight bras, or chronic stress and sleep deprivation. Focus on prevention: a good latch, regular feeding, and enough rest. If you experience mastitis multiple times, speak with a lactation consultant for a thorough review of your breastfeeding situation.

Summary: You Do Not Have to Handle This Alone

Mastitis is painful and exhausting, but with the right treatment it usually clears up quickly. Remember the three most important steps: continue breastfeeding, cool down between feedings, and take pain relief.

Seek help early if you do not notice improvement within 24 hours. Bacterial mastitis that goes untreated can develop into an abscess. With prompt treatment, the prognosis is very good.

Do not hesitate to ask for help. Your midwife, pediatrician, and lactation consultant are there for you.

Further resources:

• Guide to breastfeeding positions
• Breastfeeding equipment checklist

Sources

1. World Health Organization (WHO). "Mastitis: Causes and Management." 2000.
2. Academy of Breastfeeding Medicine. "ABM Clinical Protocol #36: The Mastitis Spectrum." 2022.
3. American Academy of Pediatrics (AAP). "Breastfeeding and the Use of Human Milk." 2022.
4. La Leche League International. "Mastitis." llli.org.