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. The color of the discharge ranges from opaque to milky.
Many medications increase levels of prolactin, the hormone that stimulates milk production.
This condition is not harmful, but your physician should be informed and a medication that does not promote a discharge may be substituted. Physiological discharge is milky, occurs in both breasts at the same time and does not vary with the menstrual cycle. If medications are not the cause, testing for the levels of prolactin in your body may help diagnose the condition. Sometimes this condition occurs in combination with amenorrhea, the absence of menstrual periods. Medications may be prescribed to correct the problem or to block prolactin production.