The Postage stamp test is a test used to evaluate nocturnal erections in a workup of male impotence.[1][2] A length of connected postage stamps connected by perforations that allow easy tearing are secured loosely around the male's flaccid penis just prior to sleeping. If the perforated connections between the individual stamps are torn upon awakening, this is taken as evidence of nocturnal tumescence. However, there is also a chance that the male may shift his position in bed in such a way as to unknowingly tear the perforated connections between the stamps without having achieved a nocturnal erection, thus causing a false positive.


  1. ^ Allan H. Goroll; Albert G. Mulley (1 December 2001). Primary Care Medicine Recommendations. Lippincott Williams & Wilkins. pp. 688–. ISBN 978-0-7817-3352-6. Retrieved 20 June 2011. 
  2. ^ Theodore A. Stern; John B. Herman; Peter L. Slavin (14 November 2003). Massachusetts General Hospital Guide to Primary Care Psychiatry. McGraw-Hill Professional. pp. 408–. ISBN 978-0-07-141001-4. Retrieved 20 June 2011.