What department to see for acute mastitis is a very common question. Acute mastitis often refers to the inflammation of the mammary glands during breastfeeding or pregnancy. Of course, this also includes breast injuries from physical trauma or parasites. Early-stage acute mastitis can manifest changes such as mild local pain and swelling, and possibly fever without other significant symptoms. Therefore, the early stage of acute mastitis can be quite confusing. In fact, one should visit the Breast Surgery department, Thyroid Breast Surgery, or Breast Thyroid Surgery department in major hospitals. If these specialties are not available, it is advisable to consult a doctor who has received advanced training in relevant fields at higher-level hospitals, typically a general surgery or gynecology specialist.