I have pain under my left breast, even hurts to the touch. Had a breast biopsy many years ago and I think it could be scar tissue. I play tennis 5-6. Times a week, I m 65 yr old female, in pretty good health, take no meds. I played tennis this morning, it didn t worsen with exercise but did feel better either. I felt a bit short of breath but it s painful and it was hot and humid (Florida) does this sound serious? Going to my nurse practitioner tomorrow. I tend to get anxious when I m not feeling well.