Nipple discharge may be associated with menstrual hormone changes. Possible causes of nipple discharge include abscess, excessive breast stimulation, fibroadenoma, papilloma, trauma, mammary duct ectasia, hormonal imbalance, galactorrhea, fibroadenosis, prolactinoma hypothyroidism, drugs, and breast cancer. Most milky nipple discharges are physiological and are not associated with any underlying disease, and does not need any treatment. Marijuana may cause nipple discharge but it is rare. I have not heard anywhere that smoking causes nipple discharge but smoking is a risk factor of breast cancer. Advice 5. Stop marijuana and smoking 6. Consult a general surgeon for physical examination of breast for any lump 7. If discharge is persistent then following investigations are required – mammography, breast ultrasound, and nipple discharge cytology Thanks