When is your pulse too high?

See a cardiologist. Many things can cause high pulse. If your pulse has suddenly gotten higher out of nowhere, and has stayed that way, it could be caused by many things. Hormone problems, anemia, or blood clots can cause high pulse out of nowhere that doesn't go down. If the cardiologist doesn't help, see another one or perhaps see a hematologist or pulmonologist. I had rapid pulse and ended up having a pulmonary embolism, which was caused by birth control, even though i was young & healthy.