The feeling is like a tingling, wave going through your body and making your head and body kind of swerve. Then heart begins to race and blood pressure seems to increase, head seems to physically swing slightly. Sometimes start to shake. I get small ones that seem to be in my head, which i can refuse and then they mentally go away. But other times, like today it became frequent, things seem to sometimes get louder or quieter. I wasn't even thinking about it, when it happened today, i was copying notes and chatting and then it came many times so i ran out.