Have you ever fainted or seen someone pass out suddenly for no apparent reason? It can be scary, especially if it seems to happen out of nowhere. And yet, some people feel fine afterward and assume it’s no big deal.
A fainting episode might seem harmless after the fact, but it can be a sign of something more serious. Here’s what fainting could mean for your health and why it’s important to seek medical help after you faint.
What happens when you faint?
“Fainting is when you suddenly lose consciousness for a short time — usually just a few seconds or minutes. It happens because your brain doesn’t get enough blood and oxygen for a moment, which causes you to black out and fall down,” said Andrea Padilla, MD, a family medicine specialist with Banner - University Medicine. You might feel lightheaded, dizzy or weak just before you pass out and your vision might get blurry.
While most people wake up quickly and feel fine afterward, that doesn’t always mean the fainting episode was nothing to worry about. Fainting, also called syncope (pronounced SING-kuh-pee), can sometimes be a sign of a health issue that needs medical attention.
What causes fainting?
Fainting can happen for many reasons. Some are simple and easy to treat, while others may need more complex medical care. Causes can include:
- Dehydration: Not drinking enough fluids can lower your blood pressure and trigger fainting.
- Standing too long or standing up too quickly: This can cause a drop in blood pressure.
- Low blood pressure or low blood sugar: These can make you feel weak and lightheaded.
- Heart problems: Irregular heartbeat or heart valve issues can disrupt blood circulation.
- Medication side effects: Some drugs can affect your blood pressure or heart rhythm.
- Strong emotions or stress: Pain, fear, anxiety or panic can cause your body to react suddenly.
- Overheating: Being too warm or being in a crowded, hot space can cause fainting.
- Medical problems: Fainting could stem from an issue with your heart, brain or blood vessels.
- Vasovagal syncope: This is a type of fainting in otherwise healthy people, including teens and young adults. It can be triggered by stress, seeing blood or standing for too long. “If you feel signs that it’s coming, such as lightheadedness, nausea or blurry vision, lying down quickly can help stop it from happening,” Dr. Padilla said.
Even if the cause seems clear, like standing up quickly or getting overheated, it’s still smart to talk to a health care provider, especially if you faint more than once.
When is fainting a sign of something serious?
Sometimes, fainting can be your body’s way of warning you about a problem. Pay close attention if you faint and you have:
- Chest pain or shortness of breath
- A fast, slow or uneven heartbeat
- Been exercising or physically active
- A family history of heart problems
- An injury from falling
- A history of anemia requiring transfusions
“These could point to heart conditions, seizures or other medical issues that need attention,” Dr. Padilla said.
Fainting could be a sign of:
- A heart rhythm problem or arrhythmia
- A structural issue with your heart
- A nervous system disorder
- Epilepsy
- Stroke
A medical exam can help find out what’s going on and whether you need further testing, treatment or lifestyle changes to stay safe and healthy.
How do doctors find out what’s causing fainting?
When you see a health care provider after you’ve fainted, they’ll ask about your health history, what you were doing when you fainted and how you felt before and after. They may perform a physical exam.
They may order tests such as:
- Blood tests: Blood tests can check for low blood sugar levels, kidney function issues, abnormal electrolyte levels and signs of anemia.
- EKG: Electrocardiograms monitor your heart rhythm. A heart monitor can track your heartbeat over time.
- Tilt-table test: This checks how your body reacts to position changes.
- Imaging tests, like brain scans: Imaging tests may help rule out neurological causes.
These tests help your provider understand what made you faint and how to keep it from happening again.
Why shouldn’t you ignore fainting?
Fainting can lead to falls, head injuries and other accidents, including auto accidents. “Fainting can sometimes be harmless, but it can also be the first sign of a serious health problem. Getting help quickly can rule out dangerous causes, prevent future fainting and injuries and provide peace of mind,” Dr. Padilla said.
What should you do if someone faints?
If someone faints, don’t leave them alone. It can help to:
- Lay them down with their legs raised.
- Call for help if it takes more than a minute or two to wake up or if they have a medical condition.
If fainting happens more than once, always see a health care provider.
We’re here to help
At Banner Health, we take your symptoms seriously. If you or a loved one has fainted, our expert team can help you find answers. From heart care to neurological support, we work with you to understand what’s causing the fainting so you can get the treatment you need. Reach out to connect with an expert at Banner Health.
