Fainting (Syncope)

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Causes

In older adults, the most common causes of fainting include:

Orthostatic Hypotension

Orthostatic hypotension is a sudden drop in blood pressure that happens when a person changes position, such as when moving from sitting to standing. A person may feel lightheaded or dizzy after standing up quickly. Causes of orthostatic hypotension include:

  • Medications, especially those used to treat high blood pressure
  • A drop in blood pressure after eating
  • Certain medical conditions, such as Parkinson’s disease or long-standing diabetes

Reflex Syncope

Fainting can occur due to carotid sinus syndrome. This condition happens when the main arteries in the neck are overly sensitive to pressure. Several factors may worsen this condition:

  • Wearing tight clothing around the neck, such as a tight collar
  • Turning the head or neck too quickly
  • Taking certain medications

Testing may be required to determine if this is the cause of fainting.

Heart Disease

Fainting related to heart problems can be serious. Causes may include:

  • Narrowing of the aortic heart valve, known as aortic stenosis
  • Irregular heart rhythms such as atrial fibrillation, or bradycardia (slow heart rate)
  • Heart failure
  • Heart attack

Other Causes of Fainting

  • Brain or nervous system conditions, including stroke or narrowing of blood vessels in the brain
  • Blood clots in the lungs
  • Bleeding, which can lower blood pressure
  • Dehydration
  • Medications. Some medications can cause fainting, especially when taken together. Your healthcare provider should review all your medications to help determine the cause.

 

Last Updated May 2026

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