A Serious Look at Fainting
Fainting is also called syncope. It's a brief loss of consciousness. It lasts just
a minute or two, followed by a quick complete recovery. This is typically linked with
a loss of postural tone which leads to falling down or needing to lie down. In an
otherwise healthy person, fainting may not be cause for alarm. But in rare cases, it
can be a sign of a serious underlying health condition. Syncope is usually caused
by a sudden drop in blood pressure or heart rate that causes decreased blood flow
to the brain. Before fainting, you may have sweaty palms, dizziness, lightheadedness,
problems seeing, or nausea.
In young people, the problem usually has no serious cause, though falls related to
fainting can lead to injury. But in some cases, it can be due to an underlying heart
problem that is more concerning. Triggers include:
Fear or other strong emotions
Standing for a long time
Suddenly standing up
Coughing very hard
Dehydration or loss of body fluid
Very rarely, stimulants, such as caffeine
Fainting in an older person, a person with heart disease, or during exertion, or while
lying down can be a cause for concern. In any of these cases you should call your
healthcare provider. It's important to diagnose the cause of the fainting.
Serious causes include:
Fast or slow abnormal heart rhythms
Coronary artery disease
Severe heart valve disease
Blood clot in the lung (pulmonary embolism)
Low red blood cell count (anemia) or blood loss
Medicine side effects
Dehydration, although this is not very common
Most people who faint stay out a few seconds to less than a minute. If the person
is unconscious for a longer time, call 911.
Common tests for diagnosis
To find out if the cause of your fainting is serious, your healthcare provider will
ask you questions about how often you faint, how long they last, and the events surrounding
the episodes. Depending on the circumstances surrounding these episodes, your provider
may order the following tests:
Electrocardiogram (ECG). This gives information about your heart rhythm and heart rate.
Echocardiogram (echo). This shows the structure of your heart, including the valves.
Orthostatic vital signs. This is where your heart rate and blood pressure are measured while you are lying,
sitting, and standing. This is to see whether there is a change related to body position.
Tilt table testing. With this test you are strapped to a table while lying flat and then steadily brought
to a standing position. Your blood pressure and heart rate are measured often to assess
for changes. You may be given medicine to provoke these changes. The overall purpose
of the test is to try to reproduce your fainting and assess if it's accompanied by
a sudden drop in blood pressure or heart rate.
Ambulatory heart monitor or implantable loop recorder (ILR). If your healthcare provider thinks that the cause of your syncope may be related
to your heart rhythm, they may have you wear a heart monitor or recommend implanting
a loop recorder underneath your skin to monitor your heart rhythm long term.
Other tests that may be done but are less common are stress testing, CT scan, and
What to do
Try to find out what things can make you faint.
Ask your healthcare provider what you can do to prevent fainting. For example, your
provider may suggest that you:
Get up slowly if you have been sitting or lying down for a long period of time. Exercising your
legs while standing for long periods may help keep your blood moving.
Have food or liquids containing salt, such as crackers, pretzels, or a sports drink.
Salt will raise blood pressure, making a sudden drop less likely. But added salt isn't
good for many people who have high blood pressure. So ask your provider before increasing
your salt intake.
Wear compression stockings
If you feel like you are going to faint:
Make sure you're in a safe place, then sit down right away so you don't fall and injure
Lie down after you've safely reached a sitting position. Prop your feet up on some
pillows or a jacket so that your feet are above the level of your heart. This raises
blood flow to the heart and in turn the brain. This is exactly what you need.
If you can't lie down, place your head between your knees to increase circulation
to your brain.
Turn onto your side to prevent choking if you feel nauseous.
If you do faint, remain lying down for 10 or 15 minutes once you wake up. Check to
see if you have a significant injury such as a bump on your head or a hip injury.
Also try moving your legs and then get up slowly.
Don't drive until your healthcare provider feels that it is safe to resume.