Often discharge from both nipples is related to hormonal changes. If this discharge has lasted longer than a month, you need to see a doctor. If it is a minimal discharge that happens in both breasts only when you squeeze your breasts, it may be within the range for normal nipple discharge. The main issue is whether this is a change from normal for you. Any breast changes that last longer than a menstrual cycle need to be checked out by a doctor. Of course, for post-menopausal women, it is important to see a doctor sooner because breast changes are less likely to be hormonal in nature. When discharge is on only one side and occurs even without squeezing, I would suggest seeing a doctor sooner rather than later. Discharge is not always cancer, but it can be one warning symptom of breast cancer.