There is a specific, physical version of nervousness that shows up on an actual exam day and does not show up during any amount of preparation at home, however seriously that preparation was taken. It is worth naming plainly rather than treating as a personal failing, because almost every candidate experiences some version of it, and the ones who perform well on the day are rarely the ones who felt nothing, they are the ones who had a real plan for functioning through it.
The morning of the exam is not the time to change anything
A specific, avoidable mistake is using exam-day morning to squeeze in one more revision pass, one more previous year paper, one more attempt to shore up a weak topic. By this point, whatever is genuinely in your memory is what will be available to you in the exam hall, and last-minute cramming rarely adds real, retrievable knowledge, it mostly adds anxiety and a sense that you are still behind. A calmer, more useful morning routine is a light, familiar one: a proper meal, arriving with real time to spare rather than rushing, and deliberately not opening notes in the final hour before the exam.
Physical logistics deserve more planning than they usually get
Knowing your exam centre's actual location, how long it genuinely takes to get there accounting for real traffic on that specific day and time, and what identification and permitted materials you need, are all things worth confirming the day before, not discovering with adrenaline already running high on the morning itself. A surprising number of otherwise well-prepared candidates lose real composure before the exam has even started because of an avoidable logistical scramble, arriving later than planned, forgetting a required document, that had nothing to do with their actual preparation.
A racing mind in the first few minutes is normal, not a sign of trouble
Opening the question paper and, for a moment, feeling like nothing you studied is coming to mind, is an extremely common experience in the first few minutes of a high-pressure exam, and it is not a reliable signal that you are actually unprepared. The usual, practical fix is to start with whatever question or section you feel most confident about, even if it was not first on the paper, since the act of writing something you genuinely know tends to settle the initial spike of nervousness faster than sitting still and waiting for calm to arrive on its own.
Build a genuine pre-exam routine, and use it consistently
A short, consistent routine in the hour before an exam, the same light breakfast, the same arrival time, the same few minutes of quiet before entering, gives your nervous system something familiar to anchor to on a day that is otherwise unfamiliar and high-stakes. This is worth building and practising before mock tests too, not inventing for the first time on the real exam day, so that the routine itself is already a source of calm rather than one more new thing to manage.