Patients often ask, "How do I know if I have erectile dysfunction?" One of the simplest and most accessible methods for anyone is to complete an online questionnaire of the International Index of Erectile Function (IIEF-5). This form is effective both for self-diagnosis and for evaluating a man's condition during a specialist consultation. The questionnaire is short and consists of five questions in various variations and orders:

  1. How do you rate your confidence that you can achieve and maintain an adequate erection?
  2. How often recently was your erection sufficient for penetration?
  3. How often were you able to maintain your erection after the start of sexual intercourse in recent times?
  4. How often were you able to maintain your erection until the end of sexual intercourse recently?
  5. How often were you satisfied when attempting to engage in sexual intercourse?

Each question should be answered on a scale from 1 to 5, where 1 is 'almost never or never/extremely difficult', and 5 is 'almost always or always/easy'. If the answer to any question implies 'did not attempt/had none', in some versions of the questionnaire, it is possible to score 0.

If the total score from the 5 questions in the erectile dysfunction test is 21 or less, there are signs of erectile dysfunction. A diagnosis is usually made if a man is unable to maintain an erection in 25% of cases of sexual activity or more.

There may also be other formulations of questions, but all of them, in one form or another, concern the man's problem in achieving and maintaining an erection until the end of sexual intercourse, as well as his level of satisfaction with himself. Often, the reason for seeking medical advice is not the fact of insufficient erection itself, but the shame, embarrassment, subjective emotional discomfort, and interpersonal relationship discord with the partner experienced due to this issue.