This is a state of anxiety and is bad for your health. Before a performance on stage, or an interview, or an exam. We have all known a really smart student who knew all the answers but flunked the test because of anxiety. Maybe you could hardly answer at the job interview. You came out perspired and heart pounding.
Some patients build up an anxiety circle .
The more the tension, the worse the anxiety , the more nervous. Certain undesirable chemicals get built up. One way to stop this is to give huge doses of nerve pills. There are many objections to this of course. Biofeedback works for these patients.