Can I learn to consciously lower my heart rate? I don't think there's anything wrong with my heart rate generally, but I've been having problems for the last few months with my pulse skyrocketing in the very specific context of the pre-blood-donation screening,and there doesn't seem to be anything I can do to stop it. I think I may have become entrenched in a horrible feedback loop of knowing I'm going to fail that part of the screening, causing me to be nervous about it, causing my pulse to speed up, causing me to fail. I've toyed with various relaxation techniques, but they don't seem to help very much, and I don't actually feel particularly nervous while my pulse is being taken, so that might be the wrong approach entirely. I only need to be able to keep below 100bpm for about a minute. Any advice or ideas about what might be going on would be greatly appreciated