What mastitis is and why it develops
Mastitis is an inflammation of the breast tissue that commonly occurs in the postpartum period in connection with breastfeeding or pumping. It can be triggered by disrupted milk flow and tissue swelling and can develop an inflammatory component. In some cases a bacterial infection is added.
Many guidelines therefore describe mastitis not as a binary condition but as a continuum from milk stasis and inflammation to bacterial mastitis and, rarely, abscess. A practical overview is the Clinical Protocol from the Academy of Breastfeeding Medicine. Academy of Breastfeeding Medicine: Mastitis Spectrum, Protocol 36
Typical symptoms: what mastitis feels like
The most important aspect is the combination of local breast symptoms and your overall condition. A blocked duct can be painful, but mastitis often brings a clear sense of being unwell in addition.
Local signs
- Pain that is noticeably worse than normal 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
- Aches, exhaustion, a general feeling of being unwell
- Rapid deterioration within hours
A patient-friendly overview of mastitis, including common symptoms and treatment, is also provided by the NHS. NHS: Mastitis
Milk stasis or mastitis: a short distinction
Many start with a localized firm area and think of a blocked duct. The transition to mastitis is often shown less by a single lump and more by the overall course.
More likely a blocked duct
- Local lump or pressure, but you otherwise feel relatively okay
- No persistent systemic symptoms
- Shows noticeable improvement with appropriate measures within 12 to 24 hours
More likely mastitis
- Fever or a strong feeling of illness develops
- Redness and pain increase and spread
- You clearly get worse instead of better
What really helps: treating mastitis calmly
The goal is to calm the inflammation, stabilise milk flow and avoid over‑stimulation. Many escalate unintentionally because they pump too aggressively or massage too hard when stressed.
Continue breastfeeding or expressing, but physiologically
In most cases it makes sense to continue breastfeeding or to express gently. Abruptly stopping can increase pressure and worsen the inflammation. The key is that emptying does not become forced or extreme.
- Feed on demand, without extra marathon sessions
- If pumping is necessary, use moderate settings and avoid maximum suction
- Vary positions to support drainage from different areas
Cooling, rest, reduce inflammation
Between feeds, many find cold packs helpful because swelling goes down and pain eases. Rest is not a luxury but part of treatment. If possible, reduce tasks for 24 hours and prioritise sleep, fluids and nutrition.
Gentle touch instead of deep kneading
Firm massage on a painful area can further irritate the tissue. It is often better to use gentle, superficial support and to reduce external pressure, for example with looser clothing and positions that avoid compression.
Antibiotics for mastitis: when they are useful
Antibiotics are not automatically the first step. They are mainly relevant when bacterial mastitis is likely or when the course does not move toward improvement.
Situations in which antibiotics are more often needed
- Marked feeling of illness and persistent fever
- Rapid deterioration despite consistent basic measures
- No clear improvement within about 24 to 48 hours
- Recurrent mastitis or specific risk factors
If an antibiotic is prescribed, that usually does not mean you must stop breastfeeding. Many antibiotics are compatible with breastfeeding, but the choice should be made by a clinician because allergies, local resistance patterns and your clinical course matter.
A useful reference on medications in breastfeeding and their evaluation is LactMed, although the specific choice should always be individualized. LactMed: Drugs and Lactation Database
When you should seek assessment
Mastitis is an area where early assessment often relieves concerns faster than days of waiting. Particularly important are the course and systemic signs.
Seek assessment if
- Fever develops or does not resolve
- You have chills, severe muscle aches or marked exhaustion
- Redness and pain increase or spread
- No clear improvement within 24 to 48 hours
- You have recurrent episodes of mastitis
Seek immediate help if
- You feel very unwell, are lightheaded or have circulatory problems
- You have severe, increasing pain with a tense, very red breast
- You suspect an abscess, for example a well‑defined, very painful, fluctuant swelling
For orientation on warning signs after childbirth that should be medically assessed, ACOG is also helpful, although interpretation is always 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, prompt assessment is important.
Common pitfalls that can prolong mastitis
- Pumping too aggressively out of fear, which can increase swelling and irritation
- Strong massage and deep kneading on the inflamed area
- Prolonged heat, which can promote swelling during inflammation
- Compression from tight clothing or pressure when lying down
- Waiting too long despite fever and marked deterioration
If you notice you are only reacting rather than getting better, that is a good signal to seek help.
Conclusion
Mastitis is more than a blocked duct because it is often accompanied by a marked feeling of illness and fever. The basics are calming the inflammation, physiological emptying, cooling and reducing pressure. Antibiotics are mainly useful when bacterial mastitis is likely or when there is no improvement. If you feel systemically unwell, have a fever or the course worsens, early assessment is the safe step.
