The exams season has begun in Scottish schools with the first of 145,000 candidates sitting Standard Grade and Higher qualifications.
More than 500 different exams will be set over six weeks
Between now and 10 June, more than 500 different exams will be set, for which 576 question papers have been prepared.
About 9,000 markers will handle some three million exam scripts.
Gaelic and accountancy are among the first tests. The biggest turnout for a single exam will be on Wednesday for Standard Grade English.
The results will be delivered on 9 August.
BBC Scotland education correspondent Seonag MacKinnon said that over the last three years, the pass rates had been fairly static.
Seventy seven per cent of fourth years pass five Standard Grades at general or credit level while 23% of fifth years pass three Highers.
The Scottish Qualifications Authority said that about 14,000 appointees contributed to National Qualifications courses and exams in roles ranging from principal assessors to invigilators.
Anton Colella, the authority's chief executive, said: "The support we receive from our appointees is outstanding.
"It really is the case that we simply could not deliver without them."
The SQA confirmed students would be able to sit national qualifications at exam centres in England, Bahrain and several European countries.
In addition, special arrangements have been made for students who are representing their country or school abroad with, for example, sports teams or orchestras.
Exam venues have been approved in 25 countries including Sweden, Spain, Cyprus, South Africa, Australia, New Zealand and the US.
The students must sit the exam at the same time as it is taking place in the UK which means, in some cases, they will be tested at unsociable hours.
Tell us your exam stories. Have you sat yours yet? How did it go? Was it what you expected or was the experience different from how you'd imagined it?
The following comments reflect the balance of opinion we received:
I am currently sitting my Higher this year. Insha Allah (God Willing) I will pass my exams. Good luck to all those sitting their exams!!!
Aisha Hussain, Glasgow
I'm about to sit my Standard Grades and am very scared and nervous. My parents and teachers have put a lot of pressure on me to succeed. I need good grades to get a high-paying job.
Jim Duggen, Buckie
My first Standard Grade exam, English, is tomorrow. I need to pass this test with flying colours if I want to take it for Higher, which I do. I am panicking quite a bit but I believe I will do ok. I wish the best of luck to all of those who are taking exams at this time. And don't worry, it will be over soon!
James Harrison, Selkirk
Nearly two decades later, I still have nightmares that I'm sitting my Highers. The scenario is this: I pull out the exam paper, only to find that the questions are in Russian (I don't speak any!). Good luck to all of you!
Jennifer Stirrup, Hertfordshire
I am doing my Highers this year and am extremly nervous. These few weeks are so important to the rest of my life, the pressure is immense! Fingers crossed it all turns out all right!
Every year, the start of the exam season still sends a shiver down my spine. Twenty years on... not sure I could do it again! Good luck everyone.
David McClelland, Glasgow
My first year of university exams starts on May the 11th and I do not envy the poor souls sitting their Highers. The subjects may not be difficult, but the unbelievable stresses placed on 16-year-old kids can't be described to someone reading the news. Best of luck to you all!
Jill MacKay, Erskine
My first exam, Standard Grade English, is tomorrow. I am worried although I hope to do well. Good luck everyone.
I am sitting my standards this year and the pressure is unbelievable - although the work is easy, we are told, compared to that of Highers - we need to do well to be able to do Highers which can then decide our future. AAAAAAAAAHHHHHHHHHHH!
Amy Gleeson, Robertson, Aberdeenshire
Well, I'm in grade 12 and am doing the IB - six subjects - and am hoping to AT LEAST manage a grade 5 in math and physics. It's hard to realise that these exams depend on your future career - mine being to become an architect. I know many students who get massive panic attacks and constantly keep crying. We totally don't deserve this stress. Doing much effort is not the same as doing the right effort.
Ashleigh McInnes, Austria
Now at my third year of university I can safely say that no matter how hard the exams your sitting are now are, the ones next year are several levels harder. However, it really isn't worth worrying over, for Standard Grades. Chances are if you're worrying, you're going to pass easily. Anyway, no pressure - two exams in next two days for me. Just work, do the exams and see what happens. It's not the end of the world regardless.
Just look on the bright side, when you get to university, at least your tuition is free.
Michael Shaw, Sheffield, UK