Fainting (Syncope) - Different Types & Causes of Fainting

The medical term for "fainting" is syncope. It is one orthostatic problem that most people know about. (Remember - orthostatic problem means getting dizzy and other symptoms when you stand up.) When it happens only once in a long while - it is not a cause for concern.

There are times and situations when fainting is something that needs to be talked about with your physician/healthcare professional.

It is time to talk with your physician when fainting happens regularly, when you get hurt fainting. It is also time to talk when you don't faint very often but you do get orthostatic symptoms (like feeling dizzy or lightheaded, weak, have vision changes) often when you stand up.

Who faints?

For people who faint more often*, the first faint happens between the ages of 10 and 30 years old. Almost half of first time fainting happens at age 15 for women. For men, the first faint happens at age 15 in about 30%. 1

The most common type of faint is called "reflex syncope".

*Some people never faint or only faint in very extreme situations.

Big question: is it due to a problem with the heart or the nerves?

If a person is fainting a lot, or it is a new problem, physicians will want to know more about what is causing a person to faint. There are 2 big concerns:

  1. What is the risk that whatever is causing the fainting will result in the person's death or a life-threatening event?

  2. What is the chance that fainting will happen again and that the person will be injured when it happens again?.


A simple way to divide the cause of fainting is to look at what is causing it:

Caused by the heart - Cardiac or Cardiovascular Syncope.

Caused by the nervous system connection to BP-pulse - "Neurally-Mediated Syncope" , also called "Reflex Syncope".

Caused by low blood pressure (BP) & slow pulse - Orthostatic Hypotension (OH). This is different kind of nerve problem.

The chance of fainting being due to a condition that is life-threatening or might cause the person's death is highest when the cause of the faint is related to the heart. It is the first thing a physician would want to rule-out. (Rule-out means do tests to make sure it isn't the cause.)

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Problem with
Type of problem
Comments How common?
Heart (cardiac)
There is a problem with the heart rate or with the heart itself (example: heart valve, growth in heart muscle)

EKG will not be normal.


It is not a common cause of fainting but it can be more serious.

11% of fainting is due to a heart rate problem, this. (11 people out of 100 will have this.)

5% of the cases of syncope. If is due to a problem with the heart muscle or valves .

Neurally Mediated Syncope (NMS)
Reflex Syncope, also VasoVagal Syncope (common faint), also Situational Syncope
Usually something sets it off,

This is the most common - 66% of cases

(Out of 100 people with fainting, in 66 of them it would be this type of fainting.)

Orthostatic Hypotension (low BP)
There is usually an autonomic nerve problem, like Parkinson's.

The blood pressure (BP) is low. If the pulse also goes slow, the person will faint.

10% - If 100 people faint, 10 will have this problem


For more information:

For a more complete list of symptoms of orthostatic intolerance (OI), go to Symptoms of Orthostatic Intolerance (OI)I.


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  1. Moya Guidelines for the diagnosis and management of syncope (version 2009). European Heart Journal (2009); 30: 2631-2671.

Author: Kay E. Jewell, MD
Page Last Updated: June 13, 2012