Erica is right; this discharge be a result of many different things. However, bloody discharge should always be taken more seriously than other kinds, as it could signal cancer. Please read our post on nipple discharge; and see the doctor soon! Good luck - PJH
First make an appt. with your doc ASAP. Better to have it checked out and be nothing, than to not have it checked out and be something! As Erica said, only someone who has seen you, examined you, and then done some testing can tell what is going on.
The cause of this could be any number of things. Was there any trauma to the area? Are you breastfeeding? Is the area red, swollen, painful? Is it coming directly from the nipple? Does it occur spontaneously or only when you touch the area?
There are a ton of questions that should be answered before even trying to make a stab at a diagnosis. I'd call your PCP or your OB/GYN and make an appt.
Lori MPAS, PA-C
No one but your doctor can tell you what the cause is definitively. Sounds like it's time to make an appointment. If this is only caused by manually expressing the blood, try not to do that before you are seen because the doctor may want to have a sample tested. Without you giving other information such as age, whether you can feel any lumps, or anything else, it is hard to say. Many things cause bloody discharge aside from breast cancer, and in fact, breast cancer only causes discharge in a few cases. You could have an infection of a duct or something along those lines. In any case, it is certainly something for your doctor to evaluate. Good luck.