What Is Carbon Monoxide Poisoning?

Carbon monoxide is a colorless, odorless gas that forms when fuel burns. Without proper ventilation, it can build up inside homes where people can breathe it in. Carbon monoxide is very poisonous. Breathing it in can lead to serious illness and even death. In fact, carbon monoxide is a leading cause of poison-related death in the U.S.

Because you can’t see, smell, or taste carbon monoxide, it’s often called “a quiet killer.” But carbon monoxide poisoning is 100% preventable. Let’s take a look at how to stay safe from carbon monoxide poisoning.

What does carbon monoxide do to the body?

Once you breathe in carbon monoxide, it enters your lungs and then your bloodstream. In your bloodstream, carbon monoxide binds to hemoglobin in your red blood cells. Hemoglobin normally carries oxygen to your organs. With carbon monoxide stuck on it, hemoglobin can’t pick up or deliver oxygen.

Without oxygen, your organs and tissues can’t function properly. If they don’t get oxygen for long enough, they’ll stop working. This lack of oxygen is why people can die from carbon monoxide poisoning. It’s like suffocating from the inside. 

What are the symptoms of carbon monoxide poisoning?

Early symptoms of carbon monoxide poisoning aren’t very specific. This makes it hard to tell if you have carbon monoxide poisoning. But most people notice:

• Headache

• Nausea

• Vomiting

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Infants, toddlers, and young children might experience even more subtle symptoms like:

• Not eating as much as normal

• Acting more cranky

• Not playing as much as usual

And because the early symptoms of carbon monoxide poisoning are so vague, many people might mistake it for a virus like the flu. So they may take a “wait-and-see” approach. But then, pretty quickly, people can develop:

• Weakness

• Confusion

• Seizures

• Loss of consciousness or be unable to wake up

When there’s carbon monoxide in a home, everyone in the home will get sick at the same time. Children and pets may get more serious symptoms faster because they’re smaller. Older people or those with chronic lung conditions, like COPD (chronic obstructive pulmonary disease), may also get more serious symptoms faster.

This is one way you can tell the difference between carbon monoxide poisoning and a regular viral illness. Usually, when a virus passes through a household, people don’t get sick at exactly the same time. If you notice everyone in your home is having these symptoms at the same time, check to make sure you don’t have a carbon monoxide leak. 

How does carbon monoxide poisoning happen? 

To understand how carbon monoxide poisoning happens, it helps to know how carbon monoxide is created. Carbon monoxide is created anytime fuel burns. Burning the following things creates carbon monoxide:

• Wood 

• Propane

• Gasoline 

• Natural gas

• Charcoal 

• Kerosene

• Oil

That said, carbon monoxide needs to be vented out of an enclosed space right away. If the gas builds up in an enclosed space — like a house or garage — people can breathe it in and get sick.

What gives off carbon monoxide in your home?

Many things that people use every day create carbon monoxide. Some of these things include:

• Vehicles that run on gasoline (like cars, motorcycles, trucks, and boats)

• All types of grills

• All types of furnaces

• Portable generators

• Gas stoves

• Machines that use gas-powered engines (like non-electric lawn mowers and leaf blowers)

• Kerosene lanterns and heaters

• Gas water heaters

• Laundry dryers

• Wood-burning stoves and pizza ovens

Even burning wood or charcoal can create carbon monoxide.

Since carbon monoxide is a colorless, odorless, and tasteless gas, it can be hard to tell if it is in your home. The first signs of carbon monoxide in your home may be someone (or everyone) in your family getting sick. That’s why it’s so important to prevent carbon monoxide poisoning in the first place. 

How can I prevent carbon monoxide poisoning?

Carbon monoxide poisoning is 100% preventable. Here’s how you can keep your family and home safe:

• Install carbon monoxide detectors. Get carbon monoxide detectors for your home. Ideally, you want at least one on each floor and in every area where someone sleeps. Check the batteries at least twice a year to make sure they are working properly. If you can’t afford carbon monoxide detectors, call your local fire department. Many fire departments have free carbon monoxide detectors to give out to the public. If you rent your home, most states require carbon monoxide detectors and smoke detectors in rental units.

• Get yearly servicing. Make sure your heating system is serviced by a qualified technician every year. They will check for any cracks or system issues that can lead to a carbon monoxide leak. Make sure to have your water heater and any gas, oil, or coal burning appliances checked, too. Get vents, flues, chimneys, and dryer vents cleaned regularly. Debris in these systems can block ventilation and lead to carbon monoxide leaks (and fires!).

• Don’t burn fuel indoors. Don’t use any kind of grill indoors or in a garage. Make sure you don’t leave your vehicle's engine running in your garage — even with the door open. If you need to use a tool that’s gasoline powered, only use it outside. Don’t try to heat your home using your stove, oven, or fuel-burning camp equipment. If you need help heating your home, talk to your utility company about assistance programs. Your state may have a “no shut off” law during colder months.

• Keep generators outside. Generators are a common source of carbon monoxide. If your power goes out, don’t run a generator inside your house or garage. Keep it at least 20 feet from your house. Running it outside a window, door, or vent can let carbon monoxide leak into your home.

How is carbon monoxide poisoning treated?

If you think there’s carbon monoxide in your home, or if your carbon monoxide detector goes off, call 911 and get everyone, including pets, out of the house right away.

Carbon monoxide poisoning requires immediate treatment in an emergency room. This is especially true if you don’t know how much time has passed since you breathed it in. Healthcare providers will measure the amount of carbon monoxide in your blood to determine the type of treatment you might need. Examples of treatment can include high flow oxygen or hyperbaric oxygen therapy.

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Written by:

Ashely Alker, MD, MSc

Ashely Alker, MD, MSc is an emergency medicine physician and nationally published writer and speaker who focuses on patient education through media and healthcare policy.

Edited by:

Patricia Pinto-Garcia, MD, MPH

Patricia Pinto-Garcia, MD, MPH, is a medical editor at GoodRx. She is a licensed, board-certified pediatrician with more than a decade of experience in academic medicine.

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