A few months ago I tried to donate blood and was unable to because my pulse was too high, 104 I think. I went back the next day, and it was 100, the cut-off for donating. I later forgot, but recently I have really noticed it. I check my pulse all the time and it is usually above 90 or around 100. Yesterday, I started having chest pain. Not a lot, I could just feel something. Today it is a little worse. It doesn't really hurt, it just feels like a tightness or pressure. I am female, about 200 pounds, not very active other than walking to class. I am only 19. Aren't I too young to be experiencing this?