The average cost of a Scottish degree is £11,284 and rising, according to a national Chain of Debt campaign that culminated in a lobby of the Scottish Parliament last week.
Some 4,000 students across Scotland filled in paper links with details of how long they had been studying and their accumulated debt so far - more than £26 million in total.
The average first-year debt is £2,843, while 62.5 per cent of fourth-year students owe £10,000 or more and 21.5 per cent owe more than £15,000.
Richard Pyle, president of Stirling University's students association, which launched the campaign, said: "I'm not sure people realise that even under the current Scottish system of student funding, we are still leaving university with debts of anything up to £18,000."
Students presented the chain to the parliament in a bid to put student hardship on the political agenda in the run-up to the Scottish elections in May.
The NUS Scotland manifesto says there must be no top up of tuition fees north of the border. And it warns the parliament not to react to English top-up fees by raising the £2,000 graduate endowment contribution beyond inflation.
The manifesto says students should earn more than £25,000 before they are liable for the graduate endowment and loan repayments, in line with the Cubie committee recommendations.
The union also wants to see an extension of grants. It argues that the parental earnings limit of £10,000 for the full grant means students whose parents earn the minimum wage could fail to qualify.
Iain Gray, Scotland's minister for enterprise, transport and lifelong learning, told a recent lifelong learning conference that he was not sure if top-up fees would deter wider access.
Mr Gray, a former teacher, said his pupils had never mentioned finance as a barrier, but would not consider higher education if none of their family had gone. He said there were no plans to introduce top-up fees in Scotland.
"There is no appetite for it in the sector and therefore it would be quite perverse to go down that road."
MSPs hear tales of students' financial hardship
MSPs being lobbied by student campaigners heard a personal account of hardship from Strathclyde University history and politics graduate Jill Collins, whose struggle to repay her debts is about to worsen.
Ms Collins is in a temporary clerical post with a £12,500-a-year salary but has applied for graduate traineeships in human resources. She is paying off a £2,000 overdraft and a £2,000 credit card bill. From next month she will be liable to start repaying about £14,000 to the Student Loans Company.
She said at the lobby last week: "You see your friends who left school at 16 and are now earning the better part of £30,000 as supermarket managers. It would be nice to be confident that you will get a better job than them, but there's no guarantee."
Ms Collins worked full time in bars during holidays and for 15 hours a week during term time for the minimum wage.
"I know a lot of people who ended up working full time and trying to do coursework on top of that."
Laura Foster, a third-year business and management student at Stirling University, is one of the coordinators of Scottish students' Chain of Debt campaign, which organised the lobby.
Ms Foster will graduate with a commercial debt of about £16,000, but says she could not have stayed in higher education without extra support from her parents. She had to abandon part-time work because her grades plummeted.
Her younger sister is considering abandoning plans to attend university.
"She sees the financial pressure I've put my parents under and knows it's going to be worse for her. She's a straight-A student but she's looking at the financial implications, which I personally do not think should be a factor," Ms Foster said.