Key Points about Fainting (Syncope)

  • Fainting is caused by a sudden drop in blood pressure and loss of oxygen to the brain.
  • Most people who faint don’t require specific treatment unless the loss of consciousness was caused by an underlying medical condition.
  • Older people are at a higher risk for fainting.
Common related conditions
Heart (Cardiovascular) Disease

Overview

Fainting – or syncope – is a temporary loss of consciousness. Before you faint, you may feel lightheaded, dizzy or nauseous. Your skin may become cold and clammy, and you lose muscle control. In most cases, people recover quickly from fainting and it isn’t cause for concerns. In rarer cases, fainting can be a sign of an underlying medical problem.

Fainting causes

Fainting is typically caused by a sudden drop in blood pressure and loss of oxygen to the brain, which can be caused by:

  • Certain medications
  • Dehydration
  • Emotional distress
  • Heart problems
  • Low blood sugar
  • Overheating
  • Standing up too quickly

Fainting risk factors

Factors that can increase your risk for fainting include:

  • Being older
  • Being under stress
  • Drinking alcohol
  • Having a heart problem
  • Having uncontrolled diabetes
  • Not drinking enough fluids
  • Taking certain medications
  • Using illicit drugs
  • Working or playing outside in hot temperatures

Fainting symptoms

The main symptom of fainting is losing consciousness. Before fainting, you may also experience one or more of these symptoms:

  • Dizziness
  • Lightheadedness
  • Nausea
  • Sweaty
  • Weakness

Fainting diagnosis

Your doctor will speak with you about your episode of losing consciousness and any related symptoms you experienced to diagnose fainting.

Fainting treatments

Most people who have a fainting spell don’t need to worry and won’t require specific treatment. If your doctor determines an underlying medical condition caused your fainting, you will need to get proper treatment for that condition.

When to seek care

If you experience any of these symptoms, start by voicing your concerns and symptoms to your primary care provider. From there, your doctor may suggest seeing a cardiologist for more specialized treatment.