Mastitis

Lactational mastitis is a spectrum of breast conditions rather than a single infection. Hyperlactation, excessive milk removal, and mammary dysbiosis can produce ductal narrowing and interstitial swelling. The resulting pressure and inflammation cause breast pain, erythema, tenderness, and sometimes fever, chills, myalgia, or tachycardia even when bacteria are not the primary driver. The older sequence—mechanical “blocked duct,” followed by milk stasis, then infection—is clinically misleading. Early mastitis is commonly inflammatory. Bacterial mastitis is a later or more severe point on the spectrum, and the same process can progress to phlegmon, abscess, or galactocele. This distinction prevents a common harmful response: trying to forcefully empty an already inflamed breast.