Near-Fainting: Vagal Reaction

Fainting (syncope) is passing out. It's a temporary loss of consciousness. Near-fainting is feeling like you are going to faint without the losing consciousness. Fainting and near-fainting can be caused by a vagal reaction. This is an involuntary response of the body to a physical or emotional stress.

This reaction causes a sudden drop in your blood pressure and a slowed heart rate. If your heart rate is slow enough, you may faint or near-faint. Lying down often stops the reaction very quickly.

These are symptoms of near-fainting:

  • Feeling lightheaded or like you are going to faint

  • Weak pulse

  • Nausea

  • Sweating

  • Blurred vision or feeling like your vision is "blacking out"

  • Fluttering heartbeat (palpitations)

  • Chest pain

  • Trouble breathing

  • Cool and clammy skin

Causes for near-fainting include:

  • Sudden emotional stress such as fear, pain, panic, or the sight of blood

  • Straining or overexertion, straining while using the toilet, coughing, or sneezing

  • Standing up too quickly, or standing up for too long a time

  • Pregnancy

  • Certain medicines

Home care

These tips will help you care for yourself at home:

  • Rest today and go back to your normal activities when you feel back to normal.

  • If you become lightheaded or dizzy, lie down right away. Put your legs up so they are higher than your heart..

  • If you are sitting down and feel faint, don't stand up. This may make the feeling worse.

  • Drink plenty of fluids, and don't skip meals.

  • Don't stand for long periods or stay in hot places.

  • Do what you can to prevent constipation. If you bear down a lot when trying to have a bowel movement, this can trigger a vagal response.

Check with your doctor to see if you need tests such as a tilt-table test, heart rhythm monitoring, or blood tests. Review the medicines you take with your healthcare provider and pharmacist to be sure the symptoms you have are not a side effect of a medicine.

Follow-up care

Follow up with your healthcare provider, or as advised. 

If you have frequent episodes of near-fainting or vagal reactions, be cautious about activities such as driving. You could harm yourself or others if you were to faint. Don't drive or operate heavy machinery if you are feeling like you may faint.

Call 911

Call 911 if any of these occur:

  • Another fainting spell not explained by the common causes listed above

  • Chest, arm, neck, jaw, back, or belly (abdominal) pain

  • Shortness of breath

  • Weakness, tingling, or numbness in one side of the face, one arm or leg

  • Slurred speech, confusion, or trouble walking or seeing

  • Seizure

  • Blood in vomit or stools (black or red color)

When to seek medical advice

Call your healthcare provider right away if you have occasional mild lightheadedness, especially when standing up.

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