After fainting, metallic taste in mouth?

Originally Published: April 9, 2004 - Last Updated / Reviewed On: February 21, 2008
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Hello Alice,

Last night my husband was having bad stomach cramps. He went to the bathroom to have a bowel movement, and while there, he fainted. I heard the crash and ran to help. After what seemed like forever, he came to, and we got him up, let him rest, then he moved to the couch. I had him go to the ER to get checked out, which they found nothing... anyway, my question for you is: when he came from the bathroom, he mentioned he had a 'metal taste' in his mouth. I've heard of this before, but can't think of what it was I heard it could be. The Dr. at the ER didn't seem too concerned, but if you have any idea, I'd like to hear what it could have possibly meant. Thanks for your time...

Lisa

Dear Lisa,

A huge number of conditions can result in fainting, including chronic low blood pressure, dehydration, use of medications such as diuretics, and a variety of more serious conditions. Similarly, a number of things could result in a metallic taste in the mouth, including bumping one's mouth during a faint and tasting blood, an extreme allergic reaction (called anaphylaxis), and a seizure. You don't mention symptoms suggestive of anaphylaxis or seizure. One of the most common reasons for the kind of fainting episode that you describe is an episode of something called "vasovagal syncope." This means a fainting episode that occurred due to overstimulation of the vagus nerve.

Vasovagal syncope occurs as a result of overstimulation of the vagus nerve, which runs from the brain, into the neck, through the chest cavity, and into the abdomen. The vagus nerve has a number of functions, including working with other nerves in the body to control both heart rate and blood pressure. When the vagus nerve is overstimulated, it can result in a sudden drop in both heart rate and blood pressure. When heart rate and blood pressure drop, the brain receives less blood and oxygen, causing someone to faint.

Some people seem to be somewhat oversensitive to stimulation of their vagus nerve, and are likely to have a vasovagal episode:

  • during urination
  • after sneezing
  • while having a bowel movement
  • in response to a stressful or emotional situation
  • during vigorous exercise

It may be that this was an isolated experience for your husband, and it may never happen again. Alternatively, he may be one of those sensitive individuals who occasionally experiences episodes of fainting. If he has any other episodes, write down as much information as you can remember about the specific conditions at the time of his episode. (What was he doing when he fainted? What had he recently had to eat and/or drink? Was he drinking alcohol or taking medications? Had he recently been ill?) If he has another episode, he needs to get a thorough check-up from his health care provider. His health care provider may be able to perform some simple tests of your husband's heart rate and blood pressure while he's lying down, sitting, standing, and/or being tilted on a table. If these tests reveal a somewhat sensitive vagus nerve, the health care provider may be able to offer information about ways to prevent such episodes. Things to avoid include:

  • becoming over-tired, dehydrated, too hungry, or overly stressed
  • standing for long periods of time without moving
  • getting up from a sitting or lying position too quickly
  • drinking or eating foods with caffeine
  • drinking alcohol

If preventive measures are not helpful, and the episodes become more frequent, the health care provider may recommend medications that may work.

Alice