Hi, I am 22 years old and I am suffering from fast pounding heartbeat from last 1 year. This happens to me after walking, climbing stairs and after lifting little weight also and the pounding heartbeat stays more than 20 minutes. It gets fast then slow then suddenly fast and slow and it freaks me out I feel thirsty and it?s like I cannot take even a single step ahead. I went to hospital in emergency they did ECG test and even the blood test they said everything is normal they just asked me to avoid caffeine but now I am anti caffeine person but still it happens to me after taking a little walk even ? please help me as I am helpless. Thanks!!!