Fainting

Fainting, or syncope, is a brief loss of consciousness when blood flow to the brain suddenly drops. Know the causes and what to do if someone faints.

This content is for informational purposes only. Always consult a healthcare professional.

Fainting is a temporary loss of consciousness. If you’re about to faint, you’ll feel dizzy, lightheaded, or nauseous. Your field of vision may “white out” or “black out.” Your skin may be cold and clammy. You lose muscle control at the same time, and may fall down.

Fainting usually happens when your blood pressure drops suddenly, causing a decrease in blood flow to your brain. It is more common in older people. Some causes of fainting include:

Heat or dehydration

Emotional distress

Standing up too quickly

Certain medicines

Drop in blood sugar

Heart problems

ⓘ Information

Before we begin: Fainting, or syncope, is a brief loss of consciousness when blood flow to the brain suddenly drops. Know the causes and what to do if someone faints.

This tutorial walks you through everything you need to know about fainting. We explain it in plain language, step by step, so whether you are a student, a patient, or simply curious, you will come away with a solid understanding.

We cover what it is, why it matters, how it is diagnosed, and what you can do about it. Key facts are called out along the way.

When someone faints, make sure that the airway is clear and check for breathing. The person should stay lying down for 10-15 minutes. Most people recover completely. Fainting is usually nothing to worry about, but it can sometimes be a sign of a serious problem. If you faint, it’s important to see your health care provider and find out why it happened.

Also known as: Syncope.

Related topics: Syncope, Vasovagal Syncope.

Categories: Brain and Nerves, Symptoms.

Source: National Institutes of Health — National Heart, Lung, and Blood Institute.

Key Takeaways

Understanding fainting is an important part of taking charge of your health. Here is what to remember:

  • Know the signs — Recognizing early symptoms can lead to earlier diagnosis and better outcomes.
  • Talk to your provider — If you have concerns or a family history of this condition, bring it up at your next checkup.
  • Stay informed — Medical knowledge evolves. Keep learning and asking questions.
  • You are not alone — Many people deal with this condition. Support groups and educational resources can help.
⚠ Caution
Medical Disclaimer: This information is for educational purposes only. Always consult a healthcare professional for diagnosis and treatment of any medical condition.