I. What is nipple bleeding? It is the spontaneous or extrusion of blood-like fluid from one or several milk ducts of the nipple, which is different from the nipple bleeding when the nipple is eczema or erosion. Second, the disease will have those nipples overflowing blood? 1, most of the nipple overflow is due to a special kind of benign tumor – breast duct papilloma, can grow one or more, a small number of duct dilatation, ductitis, etc., of course, here also need to pay attention to 10-15% of them are malignant, but also tell you do not need to panic. Most of such cases are early stage intraductal carcinoma or intraductal papillary carcinoma, and these breast cancers can be treated very well and can basically achieve clinical cure for tumor patients. 2. It should also be reminded that: the incidence of breast cancer among patients with increasing age of nipple overflow is also increasing. We have more than 3000 cases of patients with pathological nipple overflow who have received surgical treatment in our breast department, among which the percentage of patients with malignant nipple overflow over 60 years old is as high as 26%. 3. Nipple overflow can also occur during pregnancy and lactation, usually with bilateral involvement, but can also occur only unilaterally, usually in the larger side of the breast, when bilateral, no significance of the presence of serious problems, generally self-limiting, rarely lasting until 2 months after delivery, without further adjuvant examination, and only a single individual nipple overflow during pregnancy and lactation needs to receive the expected treatment, although the literature reports the finding of breast cancer in very few patients. III. What tests do I need to undergo to basically clarify what disease I have? 1. High frequency mammogram: High frequency mammogram is also the first choice for the diagnosis of patients with nipple overflow due to its high sensitivity and non-invasiveness in the diagnosis of breast cancer. In my published study on breast cancer patients with nipple overflow, I showed that the positive rate of mammogram is 32.9%, in which the characteristic malignant calcified foci are the main manifestation. If your mammogram results indicate a BI-RADS grade 4c or 5, with a large number of “white dots” (calcified spots) in the breast on the side of the overflow, you are more than 90% likely to have breast cancer and need to undergo a surgical biopsy. If your mammogram results are BI-RADS 0, then you should be happy to have another test – a breast ductal endoscopy, which is another important test for the diagnosis of nipple bleeding that can be mildly painful. The endoscope is a light in a dark tunnel, providing a clear view of the tiny lesions in the wall and lumen of your ducts from the opening to the distal 5-150px. The characteristic images under the endoscope, coupled with the magnification effect of about 10 times, make the culprit of the disease obvious, such as (Figure 2) for an intraductal breast cancer with a stiff duct wall and a “rotten” and “colorful” mass growing inside the duct under the endoscope; such as (Figure 3 ) is an intraductal papilloma, which looks like a yellow grape, moderate, and naturally benign. 3.If your mammogram and ductoscopy do not reveal any abnormality, your doctor will perform pathological cytology examination of the milk duct flushing fluid from your endoscopic examination of the milk ducts, and no malignant heterogeneous tumor cells are found in this examination. At this time, your doctor will think that the cause of your nipple overflow may be non-mastoproliferative lesions such as ductitis and dilation of the milk ducts, and suggest you to follow up with the clinic after 3 months. 4. If you have done all these examinations and no malignant signs are seen, but you are still worried at this time, you can also undergo another “noble” examination – breast magnetic resonance examination. Breast MRI has a higher specificity and sensitivity than mammography and ultrasound in the diagnosis of breast cancer, with a sensitivity of 86-100% for early breast cancer. Our hospital has one of only a few breast-specific MRI units in China, which can provide you with further clarification of the pathogenic multilayer chips of nipple overflow. If the breast MRI does not reveal any malignant signs, then now you do not need to worry about receiving close follow-up advice or surgical biopsy. Now, you understand that nipple bleeding is a problem in the ducts of the breast, but most of the ducts have benign ductal papillomas and 10-15% are breast cancers, and most of these breast cancers are early stage, which are basically clinically curable.