Research suggests prostate cancer tests can cause significant psychological distress among men.
In the first study of its kind, University of Bristol researchers tracked 330 men as they underwent the tests and afterwards.
In an article published in the British Journal of Cancer they conclude that patients should be given warnings about the distress they may experience.
Men over 45 in the UK can request a prostate test and those with high levels of the protein prostate specific antigen undergo a biopsy. There is no cancerous growth in around 70% of these cases, but 20% still found it an upsetting process.
Some men felt psychologically disturbed even after a negative result.
The research was led by Professor Kavita Vedhara, who urged health professionals to alert men to the possibilities of this.
The study adds to doubts expressed over the long-term benefits of routine prostate screening, after a 2009 study said it cuts death rates by 20% and sparked a major review of the current NHS policy of testing on request.