What mastitis is and why it develops
Mastitis is an inflammation of breast tissue that is particularly common in the postnatal period and often occurs in connection with breastfeeding or expressing. It can be triggered by disturbed milk flow and tissue swelling and can become more inflammatory. In some cases a bacterial infection is involved.
Many guidelines therefore describe mastitis not as an either/or condition but as a continuum from milk stasis and inflammation to bacterial mastitis and, rarely, abscess. A practical overview is the Clinical Protocol of the Academy of Breastfeeding Medicine. Academy of Breastfeeding Medicine: Mastitis Spectrum, Protocol 36
Typical symptoms: what mastitis feels like
The most important factor is the combination of local breast symptoms and your general condition. A blocked milk duct can be painful, but mastitis often brings a clear feeling of being unwell in addition.
Local signs
- Pain that is clearly greater than the usual pressure during breastfeeding
- Redness, warmth, swelling, sometimes wedge-shaped
- Tenderness to pressure or a firm area
- Sometimes a visible tension line or a very sensitive spot
Systemic signs
- Fever or chills
- Muscle aches, fatigue, feeling unwell
- Rapid deterioration within hours
The NHS also provides a clear overview of mastitis, including typical symptoms and treatment. NHS: Mastitis
Blocked milk duct or mastitis: a brief distinction
Many people start with a firm area and think of a blocked duct. The transition to mastitis often shows less as a single lump and more in the overall course.
More likely a blocked milk duct
- Local lump or pressure, but you otherwise feel relatively well
- No sustained systemic symptoms
- Improves noticeably within 12 to 24 hours with appropriate measures
More likely mastitis
- Fever or a strong feeling of being unwell occurs
- Redness and pain increase and spread
- You become clearly worse rather than better
What really helps: treatment for mastitis without drama
The goal is to calm the inflammation, stabilise milk flow and avoid overstimulation. Many escalate unintentionally because they pump too aggressively or massage too hard when stressed.
Continue breastfeeding or empty the breast, but physiologically
In most cases it makes sense to continue breastfeeding or to express gently. Abruptly stopping can increase pressure and worsen the inflammation. Crucially, emptying should not become forced.
- Breastfeed on demand, without extra marathon sessions
- If you need to express milk, do so moderately and not at maximum suction
- Vary positions to support drainage from different areas
Cooling, rest, reduce inflammation
Between feeds, cooling can help many people because swelling decreases and pain eases. Rest is not a luxury but part of the treatment. If you can, reduce tasks for 24 hours and prioritise sleep, fluids and food.
Gentle touch instead of deep kneading
Strong massage of a painful area can further irritate the tissue. Often more useful is gentle, superficial support and reducing external pressure, for example with loose clothing and positions without compression.
Antibiotics for mastitis: when they are appropriate
Antibiotics are not automatically the first measure. They are mainly relevant when bacterial mastitis is likely or when the course does not move towards improvement.
Situations in which antibiotics are more often needed
- Marked feeling of being unwell and persistent fever
- Rapid deterioration despite consistent basic measures
- No clear improvement within about 24 to 48 hours
- Recurrent mastitis or particular risk factors
If an antibiotic is prescribed, this usually does not mean you must stop breastfeeding. Many antibiotics are compatible with breastfeeding, but the choice should be made by a clinician because of allergies, local resistance patterns and your clinical course.
A useful reference for drugs in breastfeeding and their assessment is LactMed, although the specific choice should always be individual. LactMed: Drugs and Lactation Database
When to seek assessment
Mastitis is an area where early assessment often relieves symptoms faster than days of waiting. The course and systemic signs are particularly important.
Seek assessment if
- Fever develops or does not go down
- You have chills, severe muscle aches or marked exhaustion
- Redness and pain increase or spread
- No clear improvement after 24 to 48 hours
- You have repeated episodes of mastitis
Seek urgent help if
- You feel very unwell, are dizzy or have circulatory problems
- You have severe, increasing pain with a tense, very reddened breast
- You suspect an abscess, for example a clearly localised, very painful, fluctuating swelling
For orientation on warning signs after childbirth that should be medically assessed, guidance from ACOG can also be helpful, although assessment always needs to be individual. ACOG: Warning signs of postpartum health problems
Abscess: rare but important to know
A breast abscess is a collection of pus that can develop as a complication. It is overall uncommon but important because it usually requires targeted treatment such as drainage in addition to anti-inflammatory measures.
Clues can be a clearly defined, very painful swelling that does not improve, and a course that stagnates or worsens despite measures and possibly antibiotics. If you suspect this, timely assessment is important.
Common pitfalls that can prolong mastitis
- Too aggressive expressing out of fear, which can increase swelling and irritation
- Strong massage and deep kneading of the inflamed area
- Continuous heat, which can actually promote swelling in inflammation
- Compression from tight clothing or pressure when lying down
- Waiting too long despite fever and clear deterioration
If you notice you're only reacting rather than making progress, that's a good sign to seek help.
Conclusion
Mastitis is more than a blocked duct because a clear feeling of being unwell and fever often accompany it. The basics are calming the inflammation, physiological emptying, cooling and reducing pressure. Antibiotics are mainly appropriate when bacterial mastitis is likely or when no improvement occurs. If you feel systemically unwell, have a fever or the course worsens, early assessment is the safe step.
