This is general information, not personal medical advice. If you feel unwell or unsure, contact your GP, midwife, or 13 HEALTH (13 43 25 84).
The short version
A blocked duct is a local problem — a tender lump or sore spot in the breast, sometimes with a small patch of redness, but you generally feel okay in yourself. Mastitis is what can follow when inflammation builds: the same breast changes, plus whole-body symptoms like fever, chills and feeling flu-like. Put simply — a blocked duct is in the breast; mastitis is in the breast and in how you feel all over.
Side by side
Why the difference matters
The early, gentle care is similar for both — keep feeding comfortably, cold between feeds, avoid aggressive massage, rest and fluids. What changes is the monitoring. A blocked duct usually settles with gentle measures. Mastitis needs a closer eye, because a portion of cases need medical review and sometimes antibiotics. Knowing which one you're dealing with tells you how carefully to watch, and how quickly to act.
When to see a doctor
Seek medical care — GP, after-hours service, 13 HEALTH, or hospital — if you have any of these:
- A fever, shivering, or feeling increasingly unwell in yourself
- A red, hot area that is spreading or worsening
- Symptoms that aren't improving within about 24 hours of gentle care
- A firm, very painful lump that isn't shifting, or any breast change that worries you
Mastitis is common and very treatable — the key is not to sit on it if you're feeling unwell.
Where gentle therapy fits
For both a stubborn blocked duct and mastitis that's being medically managed, hands-on care can help settle the inflammation and support drainage alongside your GP's advice. Halotherapy is an RN-led Gold Coast service using gentle Low-Level Laser Therapy and, where useful, therapeutic ultrasound — nothing painful, and safe to combine with continued breastfeeding. Read more about blocked duct treatment or mastitis treatment, or if you're in the thick of it tonight, our guide to a blocked duct at night.
Common questions
Can a blocked duct turn into mastitis?
Yes — a blocked duct that doesn't clear can progress to mastitis, sometimes within a day or two. That's why catching it early and keeping milk moving comfortably matters.
Should I stop breastfeeding if I have mastitis?
Generally no — continuing to feed or express comfortably is usually part of getting better, not something to avoid. Your GP or a lactation consultant can guide you if feeding is very painful.
How do I know if I need antibiotics?
That's a decision for your GP, based on your symptoms and how you're tracking. If you're feverish or unwell, get reviewed rather than waiting to see.