"i am a 24 year old male who has been on dexmethylphendate 20 mg for a few years.  i find this medication is very helpful for studying but it occasionally causes panic attacks where i feel as if i am having a heart attack or stroke.  i feel my heart race and my left arm and face feel a little numb and a start shacking.  however when my doctor tests my blood pressure and ekg every thing is normal except a slightly fast heart rate."