The particularly cautious fear their decision will forge the rest of their career, and that they will one day look back on their student days and think, "I wasted my life doing something I didn't really want to do. But by the time I realised, I had invested too much time, money and effort to change direction and start again."
The reality is far different. Many jobs do not require specific degrees and employers often just see higher education as a way to prove that you have something to offer.
They are often more interested in what you achieved than in what you actually read. Forty per cent of those entering graduate employment do so in a field not directly connected to their degree subject.
For some jobs you do not need to take a particular subject. For example, you do not have to take a media studies course to go into journalism, even if you take engineering, it may still be possible to get a job in accountancy.
Other jobs do require a relevant degree, for instance if you want to be a doctor, dentist, vet or architect then you need to take the appropriate course.
You also have to consider how long you want to study for and what sort of qualification you want to take. Degrees are the most academically-based, have a higher standard of entry, and usually last for three years - in Scotland they are often four-year courses.
Some subjects require you to take a year out during your studies for instance, for language courses, you will be expected to study for a year in the relevant country to enhance language skills.
And some industrially-based subjects - for instance computer studies - include an option to spend a year in the workplace to put theory into practice.
Another thing to bear in mind is that the vast majority of degrees are now honours degrees. There are very few ordinary degrees.
It is also possible to take a Higher National Diploma in a subject. HNDs generally have a lower entry level and are more vocational.
Ross Hayman, Media Relations Officer for UCAS, explains the difference: "Both qualifications are well-received by employers. Which one to take depends very much on what you want to achieve at the end of it.
"If you have your mind set on a job which requires a degree, or if you want to study a subject of general interest then a degree would be more suitable.
"If you want to follow a more work-related period of study like business management, then perhaps taking an HND would be better."
But most importantly when choosing, do not just tie yourself down to what you were good at school, or what you think will lead to a job. You should also choose a subject that you will find interesting and a challenge.
UCAS Customer Support Manager Caroline Russell added: "It's important to make the right choice and take the right subject that is important to you. It would be three years of hell if you hated the subject.
"It's important that if it's what you are going to do for the rest of your days, then it's got to be something you like - you have got to give yourself a chance.
"You should talk to your careers adviser at school or college about taking the right course, talk to your mates, talk to your parents, talk to people who have been through higher education and find out what they thought of the subject.
"Look at all the prospects that are open to you, but you do have to make some decision eventually."
"If you are not sure about what subject to take and put down a number of different choices on your UCAS form, then do explain why, because it may be counter-productive. If you don't explain why, university admissions tutors may think you are not really committed to the subject and reject you."Reuse content