There are many reasons for nipple pressure liquid overflow, specifically analyzed as follows: 1, nipple injury, nipple is clamped or cut resulting in nipple injury bleeding, need to be pressed to stop bleeding or spray Yunnan Baiyao aerosol to stop the bleeding, and then affixed with a band-aid, if it is scratched by a knife and the wound is deeper, you need to seek medical attention to inject tetanus vaccine. 2, gestation and breastfeeding, the two special period of time the breast is stimulated by a large number of milk and accompanied by swelling of the breast, pressing the nipple will be milk out, is a normal phenomenon. The breasts are stimulated to produce a large amount of milk and accompanied by breast swelling, pressing the nipple will have milk flow, is a normal phenomenon, keep the nipple clean, to prevent eczema. 3, mastitis, breastfeeding milk stagnation in the breast, bacterial retrograde infection produces pus, nipple pressing will have pus, need to empty the breast milk in a timely manner, and oral antibiotics to alleviate the infection. 4, breast cancer, the patient has a deformation of the nipple, nipple bloody overflow, nipple distension, need to be hospitalized to fight cancer treatment. Hospitalization for anti-cancer treatment.