Studies have shown that 50 to 80 percent of nipple discharge cases are unrelated to any disease.
Most women have a small amount of discharge when their breasts are squeezed.
This is normal. Still, all discharge needs to be evaluated to determine its primary cause. Discharge production can be caused by a woman's natural hormones before her menstrual period, by sexual stimulation and by some medications. Excessive squeezing or manipulation can stimulate the breasts to produce fluid. Trauma to the breast area and surgery to the chest area can also produce discharge fluid.