Ductal fistulas, mostly caused by dilatation of the ducts with localized infectious lesions, are common, including parotid ductal fistulas and mammary ductal fistulas. 1. parotid ductal fistula: parotid ductal fistula is an oral disease, is due to injury or infection and other factors, often manifested in the parotid region of the skin with a fistula, as well as the surrounding skin flushing symptoms, and the fistula has a cool liquid outflow phenomenon. 2. Mammary duct fistula: Mammary duct fistula is the consequence of infection or tumor breakdown, the duct fistula of the mammary gland will appear in the areola region red, swollen, hot and painful, broken pus and other symptoms, abscess will recur. Generally, the nipple area is observed to have the inner concavity of the milk ducts, the inner concavity may also exist some tofu dregs cheese-like things, which is usually the typical manifestation of the breast ductal fistula. Once the symptoms of ductal fistula appear, it should be actively treated under the guidance of the doctor to avoid serious situations that may lead to adverse consequences.