What is the reason for water to flow out when the nipple is pinched?

If water comes out of the nipple when pinched, you should pay attention to this problem, especially when it is not during breastfeeding. Nipple discharge may be caused by various diseases, such as the more common intraductal papilloma, or breast hyperplasia and breast cancer, which may cause this symptom. If it is not effectively solved, the harm caused by these diseases will be relatively large.

1. Intraductal papilloma

Intraductal papilloma is more common in women aged 40-50 years old. It often occurs alone or in multiple cases in the dilated milk ducts near the nipple. The tumor is generally small, has abundant blood vessels, and is very easy to bleed. The main clinical manifestation of intraductal papilloma is watery nipple discharge; the "water" is blood-colored. Intraductal papilloma is a small tumor that is often not palpable and is therefore often discovered as a result of nipple bleeding. Intraductal papilloma is a benign tumor, but it may become malignant in 6-8% of cases.

2. Breast hyperplasia

Breast hyperplasia is the most common breast disease. Some breast hyperplasia does not require special treatment, but some breast hyperplasia, especially cystic hyperplasia, requires standardized treatment. A small number of patients with breast hyperplasia may experience nipple discharge, which is spontaneous. In a small number of patients, squeezing the nipple may reveal bloody discharge, milky white discharge, straw yellow or brown serous discharge.

Breast cancer

5% to 10% of breast cancer patients experience nipple discharge, but only 1% have nipple discharge as the only symptom. Discharge from breast cancer can vary in type and may be bloody, serous, watery, or colorless. Breast cancer that originates in large ducts or has the morphology of intraductal carcinoma is more likely to be accompanied by nipple discharge. Malignant transformation of intraductal papilloma and eczematoid carcinoma of the nipple can also cause nipple discharge. It is worth noting that although most people believe that breast cancer is rarely accompanied by nipple discharge, and even if discharge occurs, it almost always occurs after or at the same time as a lump appears, and those without a lump are rarely considered to be cancer. However, recent studies have shown that nipple discharge is an early clinical manifestation of certain breast cancers, especially intraductal carcinoma, and can exist alone before a noticeable mass forms.