There are many reasons for squeezing out yellow pus from the breast, the specific analysis is as follows: 1, sebaceous cysts, sebaceous secretions are not cleaned in time, thus blocking in the pores, forming cysts, squeezing can squeeze out white or yellow liquid. It is necessary to promptly clean the nipple and breast and surgically remove the cyst; 2, mastitis, the nipple rupture during lactation bacteria retrograde into the breast, the stagnant milk provides nutrients for bacteria, thus forming pus, pressing the breast will squeeze out the yellow pus, you need to empty the milk, while taking oral anti-inflammatory drugs or infusion of anti-infection. Surgical incision to drain the pus or puncture to drain the pus, and a high negative pressure drainage system to drain the pus after surgery; 3. Breast cancer, cancer patients will have breast pain, nipple retraction, swelling and pain, nipple overflow, and the overflow may be yellow liquid or bloody liquid, which requires surgical treatment.