A Serious Look at Fainting

A Serious Look at Fainting 

Fainting, also called syncope (SIN-koh-pee) is 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 because 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:

  • Severe stress

  • Fear

  • 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

  • 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 determine whether the cause of your fainting is serious your doctor 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 doctor may order the following testing:

  • 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 laying, sitting, and standing to see whether there is a change related to body position
  • Tilt table testing. With this test you are strapped to a table while laying flat and then steadily brought to a standing position. Your blood pressure and heart rate are measured frequently 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 for whether it's accompanied by a sudden drop in blood pressure or heart rate.
  • Ambulatory heart monitor or implantable loop recorder (ILR). If your doctor thinks that the cause of your syncope may be related to your heart rhythm he or she may have you wear a heart monitor or recommend implanting a loop recorder to monitor your heart rhythm long term.

    Other tests that may be done but are less common are stress testing, CT scan, and MRI.

What to do

  • Know which 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 yourself.

    • 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--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

Online Medical Reviewer: Steven Kang MD

Online Medical Reviewer: Quinn Goeringer PA-C

Online Medical Reviewer: Lu Cunningham

Date Last Reviewed: 3/1/2019

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