I have been having an increased heart rate with the sudden need to go number 2, i also feel as if I am having trouble breathing, dry mouth and feel light headed as if I was going to faint. This has happened 3 times now 2 were almost 2 weeks apart and the next was the next day but was't as intense as the second one I had. I monitored my heart rate today before the minor one where my heart rate went from 79 to 113 bpm. I do not know why this is happening doctor thought it was because my iron was a little low but I have been taking Iron Vital F every morning and it is still happening.