Last week, my husband fainted while urinating. His doctor said he might have micturition syncope. What causes this, and what can he do about it?

Answer From Phillip A. Low, M.D.

Micturition syncope, also known as post-micturition syncope, is fainting while urinating or immediately after urinating. This is likely due to a sudden, severe drop in blood pressure. Micturition syncope is most common in older men. It happens most often when getting up at night from a deep sleep.

The exact cause of micturition syncope isn't fully understood. But it may be related to a fall in blood pressure when you get up suddenly and stand at the toilet. Or this may happen when a full bladder empties very quickly. This is thought to cause a sudden drop in blood pressure.

Other factors that may play a role in micturition syncope include:

  • Alcohol.
  • Dehydration.
  • Fatigue.
  • Hunger.
  • Medical conditions, such as a respiratory infection.
  • Urinate slowly without straining.
  • Use of alpha blockers to improve urination in men with prostate problems.

Preventing micturition syncope

Micturition syncope isn't very common. It should be checked by a healthcare professional because it may mean that there is an underlying medical condition. Prevention of micturition syncope depends on recognizing the factors that contribute to micturition syncope and avoiding them.

To avoid micturition syncope and a possible injury, you might suggest some of these strategies to your husband:

  • Ask your healthcare professional whether any medicines you're taking may be causing your condition.
  • Avoid excessive amounts of alcohol.
  • Don't get out of bed suddenly. Sit on the edge of the bed, move your legs, and make sure you aren't dizzy or lightheaded.
  • Urinate sitting down.


Phillip A. Low, M.D.

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April 23, 2024 See more Expert Answers