What is carbon monoxide poisoning?

Carbon monoxide (CO) is an odorless, colorless, tasteless gas found in fumes emitted during partial combustion. Such fumes can come from car and truck engines, small gasoline engines, gas stoves, lanterns, and heating systems (including home furnaces). CO fumes also can result from the charcoal, kerosene, propane, or wood.

Red blood cells in the body take in CO faster than oxygen, crowding out oxygen in the bloodstream. CO poisoning occurs when vital organs— such as the brain and heart— are deprived of the oxygen they need. In addition, CO can combine with proteins in the body and cause tissue damage. In both instances, serious injury or death can result from just a few minutes of exposure to high levels of CO.

How common is carbon monoxide poisoning?

Each year in the United States, accidental CO poisoning kills more than 400 people. An additional 20,000 people are sent to emergency rooms and more than 4,000 must be hospitalized due to CO poisoning.

The most at-risk groups are unborn babies, infants, people living at high altitudes, those with chronic heart disease, anemia or respiratory problems, and people with already-elevated CO levels such as smokers. Most deaths occur in those over the age of 65.

What causes carbon monoxide poisoning?

When properly maintained and used correctly, appliances that burn fuel will usually not emit levels of CO that are harmful. The incorrect use of fuel-burning appliances or using such appliances when they are not properly vented or leak fumes can be dangerous.

Idling cars and trucks in enclosed areas or vehicles with an obstructed exhaust system (such as snow in the tailpipe) can also be hazardous.

What are the symptoms of carbon monoxide poisoning?

At low levels of CO exposure, symptoms can be confused with those of the flu, food poisoning, or other illnesses. Symptoms include the following:

At moderate levels of CO exposure, symptoms include:

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