Single-hole nipple discharge should be paid more attention to, which can be seen in intraductal papilloma, breast cancer, cystic hyperplasia of the breast, etc., and also combined with the nature of the discharge, clinical expression, etc. to determine. 1. Intramammary ductal papilloma: it occurs in women who have given birth, the tumor is easier to bleed, and the common first symptom is nipple discharge. It is mostly found on underwear, and its nipple overflow can have various expressions, such as bloody, yellow, dark brown and so on. The treatment method is mainly surgical treatment, and the postoperative review should be timely. 2. Breast cancer: there are various types of breast cancer, including non-invasive cancer, invasive specialized cancer, invasive non-specialized cancer, etc. Its main manifestation is breast lump, and it may have nipple discharge, which is mostly single-hole and mainly bloody. The treatment method is surgery supplemented by chemotherapy. 3. Breast cystic hyperplasia: mainly occurring in middle-aged women, the common manifestations are breast swelling and pain, related to menstruation, as well as nipple discharge, most of which is plasma. The main treatment is symptomatic treatment, can use tamoxifen and other drugs. It is important to seek medical attention for uniportal nipple discharge and follow medical advice.