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Carbon monoxide is an odorless gas that causes thousands of deaths each year in North America. Breathing in carbon monoxide is very dangerous. It is the leading cause of poisoning death in the United States.
This article is for information only. DO NOT use it to treat or manage an actual poison exposure. If you or someone you are with has an exposure, call your local emergency number (such as 911), or your local poison center can be reached directly by calling the national toll-free Poison Help hotline (1-800-222-1222) from anywhere in the United States.
Carbon monoxide is a chemical produced from the incomplete burning of natural gas or other products containing carbon. This includes exhaust, faulty heaters, fires, and factory emissions.
The following items may produce carbon monoxide:
Note: This list may not be all-inclusive.
When you breathe in carbon monoxide, the poison replaces the oxygen in your bloodstream. Your heart, brain, and body will become starved of oxygen.
Symptoms vary from person to person. Those at high risk include young children, older adults, people with lung or heart disease, people who are at high altitudes, and smokers. Carbon monoxide can harm a fetus (unborn baby still in the womb).
Symptoms of carbon monoxide poisoning may include:
Animals can also be poisoned by carbon monoxide. People who have pets at home may notice that their animals become weak or unresponsive from carbon monoxide exposure. Often the pets will get sick before humans.
Since many of these symptoms can occur with viral illnesses, carbon monoxide poisoning is often confused with these conditions. This can lead to a delay in getting help.
If the person breathed in the poison, immediately move him or her to fresh air. Seek immediate medical right away.
Install a carbon monoxide detector on each floor of your home. Place an additional detector near any major gas-burning appliances (such as a furnace or water heater).
Many carbon monoxide poisonings occur in the winter months when furnaces, gas fireplaces, and portable heaters are being used and windows are closed. Have heaters and gas-burning appliances regularly inspected to make sure they are safe to use.
The following information is helpful for emergency assistance:
However, DO NOT delay calling for help if this information is not immediately available.
Your local poison center can be reached directly by calling the national toll-free Poison Help hotline (1-800-222-1222) from anywhere in the United States. They will give you further instructions.
This is a free and confidential service. All local poison control centers in the United States use this national number. You should call if you have any questions about poisoning or poison prevention. You can call 24 hours a day, 7 days a week.
The health care provider will measure and monitor the person's vital signs, including temperature, pulse, breathing rate, and blood pressure. The person may receive:
Carbon monoxide poisoning can cause death. For those who survive, recovery is slow. How well a person does depends on the amount and length of exposure to the carbon monoxide. Permanent brain damage may occur.
If the person still has impaired mental ability after 2 weeks, the chance of a complete recovery is not very good. Impaired mental ability can reappear after a person has been symptom-free for 1 to 2 weeks.
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Little M. Toxicology emergencies. In: Cameron P, Jelinek G, Kelly A-M, Brown A, Little M, eds. Textbook of Adult Emergency Medicine. 4th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2015:chap 29.
Nelson LS, Hoffman RS. Inhaled toxins. In: Marx JA, Hockberger RS, Walls RM, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 8th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 159.
Reviewed By: Jacob L. Heller, MD, MHA, Emergency Medicine, Virginia Mason Medical Center, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.