Sometimes my heart start beating really fast and i feel a bit dizzy for no reason at all. it lasts for abt a few minutes. i'm 19 shld i be worried?

Need to see a doctor: Hearts should not suddenly go very fast without reason. A primary doctor can evaluate the heart and see if there are reasons to have a fast rate. The doctor may refer to a cardiologist to do a 24-hour monitor, which you wear for a day to record all the heart rates. Some causes are not dangerous, but other causes are. Meanwhile, one should live carefully, as sudden rapid rates can cause fainting.