Understanding Syncope

Syncope (pronounced sin-ko-pee) is the medical word for fainting. It happens when not enough blood flows to the brain, causing you to pass out for a short time. Some people may feel dizzy and almost faint, while others might fall down and get hurt

There are many reasons why someone might faint. Most causes involve something that lowers blood flow to the brain, such as:

  • A sudden drop in blood pressure
  • A very slow or fast heart rate
  • Problems with the heart or nervous system

  1. Vasovagal Syncope (Reflex syncope)
    This is the most common kind. It can be triggered by things like:
      • Seeing blood
      • Strong emotions
      • Pain
      • Coughing or using the bathroom
        These triggers cause the body to suddenly lower blood pressure, leading to fainting.
        These triggers cause the body to suddenly lower blood pressure, leading to fainting.
  2. Postural (Orthostatic) Hypotension
    Standing up too fast can cause blood pressure to drop, making you faint.
  3. Cardiac Syncope
    A problem with the heart’s rhythm (too fast or too slow) or heart disease can cause fainting.
  4. Neurologic Syncope
    Conditions like seizures or strokes may lead to passing out.
  5. POTS (Postural Orthostatic Tachycardia Syndrome)
    When standing up causes a big increase in heart rate, sometimes leading to fainting.

People may feel different symptoms before passing out:

  • Dizziness or lightheadedness
  • Blurry or tunnel vision
  • Feeling sweaty or nauseated
  • Seeing spots
  • Heart pounding (palpitations)
  • Feeling weak or about to fall

With vasovagal syncope, you may feel nauseated or lightheaded before fainting. With cardiac syncope, you may feel your heart racing first.

Most of the time, fainting is not dangerous—especially when there is a clear cause, like with vasovagal syncope. But it can be serious if it:

  • Happens without warning
  • Is caused by a heart condition If you faint often or without a clear reason, it's important to get checked.

If you faint often or don’t know why it happens, you should go see a doctor and get it checked out.

Doctors use different tests to find the cause:

    • Electrocardiogram (EKG) – checks your heart rhythm
      • Echocardiogram – takes ultrasound pictures of your heart
      • Heart monitor – a patch or device worn to record your heartbeat for days/weeks/years
      • Blood tests – check for problems like low sugar or salt levels
      • Tilt table test – checks your heart rate and blood pressure as your body position changes
      • Autonomic testing – checks how your body controls automatic functions like blood pressure, heart rate, sweating response, and pupil activity
      • Electrophysiology (EP) study –invasively checks how the heart’s electrical system works
      • EEG or brain MRI – used if doctors think it’s a brain issue like a seizure or stroke

Treatment depends on the cause:

  • Vasovagal Syncope:
    • Drink plenty of fluids
    • Avoid triggers (like standing too long or hot showers)
    • Use compression socks or an abdominal binder
    • In rare cases, if symptoms are severe with confirmed a dramatic drop in heart rate or development of heart block, a pacemaker or ablation may be considered
  • Heart-related Syncope:
    • May need further tests or procedures, like an EP study or coronary evaluation
    • If the heart rate is too slow, a pacemaker may help

Yes! If you feel it coming on (called a "prodrome"), you can try:

    • Lying down and lifting your legs
    • Crossing your legs and squeezing your muscles
    • Making fists or tensing your arms

These tricks help raise your blood pressure and may stop the fainting from happening.

Sometimes. For vasovagal or orthostatic syncope, medicines may help if lifestyle changes don’t work:

  • Fludrocortisone – helps your body hold onto salt and water, raising blood pressure
  • Midodrine – tightens blood vessels to raise blood pressure
  • Droxidopa – turns into norepinephrine, which helps with blood pressure and works in the brain

Yes, in some cases—if your heart rate drops very low and causes you to faint, a pacemaker can help keep your heart beating regularly.

Yes! You can:

  • Drink more water
  • Avoid alcohol and caffeine
  • Eat enough salt (if your doctor says it’s safe)
  • Stand up slowly
  • Avoid standing for long periods