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Near-Fainting With Uncertain Cause

Fainting (syncope) is a temporary loss of consciousness. It's often called passing out. It happens when blood flow to the brain is reduced. Near-fainting (near-syncope) is like fainting, but you don't fully pass out. Instead, you feel like you are going to pass out but don't lose consciousness.

Signs and symptoms

If you have symptoms of near-fainting, you may feel:

  • Lightheaded or like you are going to faint.

  • A weak pulse.

  • Nausea.

  • Sweating.

  • Blurred vision or feeling like your vision is fading.

  • Palpitations.

  • Chest pain.

  • Trouble breathing.

  • Cool and clammy.

Causes

Fainting usually happens when your blood pressure or heart rate suddenly drops and not enough blood flows to your brain.

Common minor causes include:

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

  • Straining or overexertion, such as straining while using the toilet, vomiting, coughing, or sneezing.

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

More serious causes include:

  • Very slow, fast, or irregular heart rate (arrhythmia).

  • Dehydration.

  • Significant blood loss.

  • Medicines, or a recent change in medicines. Medicines that can cause fainting include blood pressure or heart medicines.

  • Heart attack.

  • Heart valve problems.

Even minor causes can become serious if you fall and injure yourself or you are driving. You may need more tests. It's very important that you follow up with your health care provider as advised.

Home care

These guidelines will help you care for yourself at home:

  • Rest. You can go back to most of your normal activities as soon as you are feeling back to normal.

  • If you become lightheaded or dizzy, lie down right away or sit with your head between your knees.

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

Because the exact cause of your near-fainting spell is not known, another spell could occur without warning. To stay safe, don't drive a car or use dangerous equipment. Don't take a bath without someone close by. Don't swim alone. You can resume these activities when your health care provider says that you are no longer in danger of having a near-fainting spell.

Follow-up care

Follow up with your health care provider, or as advised.

Call 911

Call 911 or get emergency care if any of the following occur:

  • Another near-fainting or full fainting spell occurs, and it's not explained by the common minor causes listed above

  • Chest, arm, neck, jaw, back, or abdominal pain

  • Shortness of breath

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

  • Slurred speech, confusion, trouble walking or seeing

  • Seizure

When to get medical advice

Call your health care provider for advice if any of these occur:

  • Changes in your medicines

  • You start to have near-fainting more often

Online Medical Reviewer: Marianne Fraser MSN RN
Online Medical Reviewer: Rajadurai Samnishanth Researcher
Online Medical Reviewer: Robyn Zercher FNP
Date Last Reviewed: 3/1/2025
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