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Carbon monoxide poisoning

Carbon monoxide poisoning occurs when carbon monoxide builds up in the blood. When too much carbon monoxide is in the air, the body replaces the oxygen in the red blood cells with carbon monoxide. This can lead to serious tissue damage, or even death.

Carbon monoxide is gas that has no odor, taste or color. Burning fuels, including gas, wood, propane or charcoal, make carbon monoxide. Appliances and engines that aren’t well vented can cause the gas to build up to dangerous levels. A tightly enclosed space makes the buildup worse.

Anyone exposed to carbon monoxide needs to get into fresh air and seek medical care right away. Call emergency medical services (EMS) or dial 911 right away for someone who’s in a coma or can’t respond.

Carbon monoxide poisoning affects the brain and heart the most. Exposure over time might lead to symptoms that can be mistaken for the flu without the fever. Clearer symptoms of carbon monoxide poisoning can include:

Symptoms related to the nervous system and brain can come on after recovery from carbon monoxide poisoning. The risk of these is higher in people who lost consciousness from the carbon monoxide and older people. Symptoms might include:

Carbon monoxide poisoning can be especially dangerous for people who are asleep, drugged or drunk. Carbon monoxide can cause brain damage or death before anyone realizes there’s a problem.

When to see a doctor

For possible carbon monoxide poisoning, get into fresh air and seek medical care right away.

Many fuel-burning products and engines make carbon monoxide. Most often the amount of carbon monoxide from these sources isn’t cause for worry in areas with good air flow. But if they’re used in a partly closed or closed space, the carbon monoxide level can be a danger. Examples are using a charcoal grill indoors or a running car inside a garage.

Breathing the fumes causes carbon monoxide to replace oxygen in the blood. This prevents oxygen from getting to tissues and organs.

Breathing in smoke during a fire also can cause carbon monoxide poisoning. And smoking through a water pipe, called a hookah, has been linked to increasing numbers of younger people getting carbon monoxide poisoning.

Breathing in carbon monoxide can be especially dangerous for:

Damage from carbon monoxide depends on how much is breathed in and for how long. Carbon monoxide poisoning can cause:

To help prevent carbon monoxide poisoning:

Treatment is likely to start right away for anyone brought to an emergency room with suspected carbon monoxide poisoning. To confirm the diagnosis, the health care team might test a blood sample for carbon monoxide. This test should be done as soon as possible after removing the person from the suspected exposure environment. But the test shouldn’t delay treatment.

Get into fresh air right away. Call 911 or emergency medical help if you or someone with you has symptoms of carbon monoxide poisoning. These include headache, dizziness, nausea, shortness of breath, weakness and confusion.

At the hospital, treatment may involve:

If you or someone you’re with has symptoms of carbon monoxide poisoning, get into fresh air immediately and call 911 or emergency medical help. Symptoms can include headache, dizziness, nausea, shortness of breath, weakness and confusion.

The health care team at the hospital will need information as soon as you arrive. On the way to the hospital, try to prepare to answer questions about:

© 1998-2024 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved.

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