Feeling my heart beat more often

No other symtomns

But it does increase to 100-120 when i walk and i notice it soemtimes in 80s when im laying sowmtimes when higher

Um when im taking showere tho my hr goes up to 130-153 accoesing tk my watch the higher the temp the more it can be 120s 130s 140s & for few secs 153 is this nornal im 21 and need to walk/go out more thats all