I recently donated plasma last Friday late afternoon around 3:30pm. I had a little bruising, but no big deal. I was slightly dehydrated, so I drank around 4 16oz. of bottled water. The next morning when I woke up and got out of bed, I noticed a heavy, painful feeling around my nipple on my left breast. I felt around and immediately felt a small lump that was hard and when I pressed on it, was very painful. I m not a mother, I m 44 years old and in very good health. In 1992 I had a benign cyst removed (11 o clock if looking straight on at the breast) from that left breast. I have scar tissue that is hard, but the new, small lump I felt is just at 9 o clock. It was painful all day long. I took some ibuprofen and the pain subsided greatly. I wear a wire, kind of tight, sports bra when I walk my dog in the morning. I was very sweaty, so I thought I may have a clogged sweat duct or something. I know breast cancer just doesn t develop overnight. I ve never felt these lumps before. I ve stopped drinking coffee (I only have a cup a day M-F), I had a lot of milk chocolate the other week, but that was just a one-time indulgence. I read that it may be IBC, but I m not sure. I also read it may be a blood-filled area on the breast that s clogged. I was thinking it may have something to do with when I donated plasma. The BP cuff was at 50 in order for the plasmapheresis to work and my arm was very achy afterwards. I thought maybe my arm being in a certain position for over 45 minutes, that I may have ruptured something in my breast? I m grasping at straws here doc. Any suggestions?