What Is Syncope? - Definition, Causes & Symptoms

Instructor: Danielle Haak

Danielle has a PhD in Natural Resource Sciences and a MSc in Biological Sciences

Syncope is the medical term used for ~'blacking out~' or ~'fainting.~' Check out this lesson to learn more about what causes syncope, how it can vary, and some of its common symptoms.

What Does Syncope Mean?

Have you ever experienced syncope (pronounced 'sin ko pea')? Syncope is the term used to describe when a person loses consciousness after a temporary decrease in blood reaching the brain. This is commonly referred to as fainting. Syncope has an interesting history: when fashion trends included tight corsets, women often lost consciousness and resorted to fainting couches.

A person may faint if they experience a drop in blood pressure, a change in heart rate, or changes in blood circulation or volume. Loss of consciousness is typically short term, and the person will most likely 'come to' within a few seconds or minutes. However, multiple episodes of syncope could be indicative of circulatory, heart, or neurological conditions.

Causes and Types of Syncope

When the amount of blood reaching the brain dramatically decreases, a person may lose consciousness and fall over. Changes in blood circulation, pressure, and volume, as well as heart rate, can all cause bouts of syncope.

There are different types of syncope. Vasovagal syncope, or cardio-neurogenic syncope, is the most common form. Certain medical conditions, like orthostatic hypotension, may prevent the blood vessels from constricting normally. This can cause blood to pool in the lower extremities, instead of making its way to the brain.

Situational syncope is a specific kind of vasovagal syncope that occurs only during certain situations. Triggers include severe anxiety, fear, or stress; dehydration, pain, and hunger. Alcohol and drug use can also trigger situational syncope.

Postural syncope, or postural hypotension, occurs when blood pressure drops quickly, such as when you stand up too suddenly. Dehydration and medications can also cause postural syncope. Cardiac syncope can happen when there is a blood vessel or heart condition that prevents blood from reaching the brain, such as a blood clot or an arrhythmia. By comparison, a neurologic syncope occurs when someone has a migraine headache, seizure, stroke or some other brain-related event.

19th-century fainting couch

To unlock this lesson you must be a Study.com Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use Study.com

Become a Study.com member and start learning now.
Become a Member  Back
What teachers are saying about Study.com
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account