Fainting often happens when your brain has a short-lived decrease in blood flow.
Fainting can be a symptom of one or more possibly serious health problems. Some causes are harmless, and others can cause death.
In older adults, the most common causes of fainting are:
Orthostatic Hypotension
This means a quick drop in blood pressure. People sometimes can feel lightheaded after standing up quickly, due to a quick drop in blood pressure. Causes of orthostatic hypotension include:
- Medications, often those used for high blood pressure.
- A drop in blood pressure right after eating.
Reflex Syncope
Fainting can be caused by carotid sinus syndrome. This syndrome happens when the major arteries in a person’s neck are very sensitive to pressure. Several things may make this syndrome worse:
- Wearing something tight around the neck, like a tight collar.
- Turning the head and neck too quickly.
- Taking certain medications. Testing may be needed to find out if this is the cause of syncope.
Heart Disease
Fainting related to heart problems can be serious. It can be caused by:
- Narrowing of the aortic heart valve (called aortic stenosis).
- Irregular heart rhythms.
- An unusually low heart rate (also called bradycardia) is often the cause for older adults. Bradycardia is a heart rate of less than 60 beats per minute.
- Heart failure.
- Heart attack.
Other Causes of Fainting
- Conditions of the brain or nervous system, including strokes or narrowing of the blood vessels in the brain.
- Blood clots in the lungs.
- Bleeding.
- Dehydration. As a person ages their kidneys don’t function as well as they used to. They often don’t drink enough liquids because they don’t feel thirsty. This can lead to dehydration, which can lower your blood pressure.
- Medications. Drug side effects and how they interact with each other can cause fainting. A medication review is important if you have fainting.
Last Updated December 2022