I tend to think pressure is all over the place with students today. Exams seem to turn aspiring boys, girls, men and women into highly stressed individuals, even though they're hungry to achieve what they want to do for a living.
Exams shouldn't be looked at as a hurdle in the way of progress, they should be seen as gateways towards what you want to do. Of course people get side-tracked with their revision due to life matters, but if you have control over the situation, you'll overcome whatever an exam throws at you.
You need discipline and you need to believe in your abilities and what you want to achieve. You may hate maths, but if you endure maths and get a grade 7 or 8, then it'd all be worth it because then your job prospects open up widely.
Most importantly, no matter what an exam throws at you, there's always a way forward afterwards. Exams are never a be all end all. I know a few select positions demand the highest grades in exams, but they are only for the specialist positions, not for every desirable jobs out there.
We are immensely more powerful than any icky exam. If you worry about exams think about the benefits of taking the exam and the potential rewards of doing well, and totally wipe out all the negativity and the pressure-those things stymie concentration and performance.
Remember exams are about YOU, nobody else!