Unison’s annual student survey showed almost a quarter of those surveyed owed more than £10,000.
Nursing diploma students are starting their careers owing an average of 40% of their annual salary, which would take seven years to repay at £100 a month.
Of those surveyed, said they were considering quitting because of financial hardship.
Black and ethnic minority students are more severely affected by financial pressure, with 74% considering leaving.
Gail Adams, Unison head of nursing, said: ‘This survey has very worrying implications for the future health of the NHS. Students are simply not getting enough financial support.
‘With one third of nurses due to retire in the next 10 years, and the number of health professionals coming from overseas to work in the UK falling, urgent action is needed to avoid a serious skills shortage.’