It can cover anything from being nervous in an exam of any kind & not performing to the standard you know you can. It can come from a previous bad experience, someone else or yourself having too high expectations (perfectionism) or a number of reasons. You can benefit from a comprehensive exam stress course of advice & hypnosis techniques that Dave has studied a passed a course on from Dr Richard Nonguard.
A lot of students cram at the last minute, drink coffee and stronger things & stay up all night revising the night before an exam so they’re not in the best shape for it when they get there. The way we learn best is to absorb by repetition, that means we do it effortlessly, like how we learnt our native language as we grew up. It only takes 21 repetitions over approx the same number of days to make something a habit, and only a few minutes a day revising a subject (or even just thinking about it once it’s understood by the conscious mind and a trace has been laid down in long term memory which is then strengthened by use). We also build deeper understanding of a subject on top of basic ideas which have to become unconscious competence before the new ideas have somewhere we can hang them, it’s the understanding that keeps our interest and increases the ability to remember almost everything because it makes sense, rather than attempting to memorise a list of facts at the last minute which have little meaning without the bigger picture.
The mind can be prepared with hypnosis. I've inserted a screenshot from an abstract of a research article below. But first make sure your body is prepared as this supports brain funcion. Eat right. And if you can’t eat right then supplement. Give it time to digest before an exam. Sleep right, usually 8 hours minimum for a few days before even if you normally burn the candle at both ends. Drink water for sustained energy & hydration & don’t rely on energy drinks as you’ll risk getting the crash at the worst time, in the middle of the test. Don’t believe the hype about what they can do. Same with heavily sugared ones like coke, and the diet ones can produce an insulin reaction because the body reacts to the sweet taste and hence can produce another crash. Vitamin B6 helps neurological functions so if you think you're not getting enough of this in your diet then take a supplement.