The most minor of stage fright levels, the butterflies in the stomach describe the nervous feeling that a performer gets just before the performance. Some artists say this low level of anxiety is actually a positive, motivating factor as it demonstrates they care about performing well. This stage is typically characterized by worry over the performance and a restlessness that may lead to pacing, tapping one's foot or wringing one's hands.
This more moderate level of stage fright begins to take on more physical symptoms. The person suffering this level of stage fright may find himself trembling, palms sweating, experiencing nausea, his heart rate increasing, and his knees and legs getting weak. A musician might experience dry mouth. This level of stage fright can often interfere with performances because of the physical effects. If not curbed at this point, stage fright can grow into the later and more severe levels.
The third level of stage fright is quite serious and can affect the performance of the individual experiencing it and everyone around her. It is characterized by panicky thoughts, a cold sweat, a severe headache, vomiting and an inability to focus. A person suffering an anxiety attack may have difficulty breathing and be unable to perform until the anxiety attack passes.
The final stage of stage fright is that of abject terror. The person is unable to move and often unable to speak. The performer may faint or simply disassociate psychologically from his surroundings. This level of stage fright usually is brought on by a severe phobia and may require psychological or medical intervention to overcome.