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First Aid: Carbon Monoxide Poisoning, The Silent Killer

First Aid: Carbon Monoxide Poisoning, The Silent Killer

Carbon monoxide poisoning is more common than many people think. Because carbon monoxide is a colorless, odorless gas, it often goes unnoticed until it is too late. To make matters worse, there are many common household sources of carbon monoxide that your family may be easily exposed to. Learn more about this silent killer and how to treat it in an emergency.

How does carbon monoxide poisoning happen?

Carbon monoxide is made up of one carbon atom and one oxygen atom. Alone, these elements are essential and definitely not harmful. To understand why carbon monoxide causes toxicity, we need to understand how our lungs and gas exchange works in our bodies.

Gas exchange in the lungs

Normally, when we inhale, we take in oxygen (O2). This oxygen enters our lungs and passes into our bloodstream attached to red blood cells (RBCs). Each RBC holds up to 4 oxygen molecules.

As the RBCs make their way to different parts of our body, they drop off the oxygen and nutrients and take away carbon dioxide (CO2) and other waste products.

The RBCs eventually return to the lungs where they release the CO2 and pick up new oxygen. When we exhale, we release the carbon dioxide. This cycle then restarts and continues even while we are sleeping.

What does carbon monoxide do?

When we breathe in carbon monoxide instead of oxygen, the carbon monoxide binds to the RBCs irreversibly.

This means that instead of carrying and exchanging oxygen and carbon dioxide to the organs of the body, carbon monoxide never leaves the RBC. Without oxygen and nutrients, different cells and organs of the body will die. If the carbon dioxide and waste products are not removed, this causes build-up within the cells and also results in cell death.

Respiratory Health: Everything You Need to Know

Signs and symptoms to watch out for

Depending on the amount of exposure to carbon monoxide, symptoms of CO poisoning can be experienced in a matter of minutes. The earliest and most common symptoms include headache, dizziness, weakness, upset stomach, and chest pain.

Confusion and loss of consciousness also occur once the brain becomes deprived of oxygen. Some people may fall unconscious before noticing the other signs and symptoms. This may be mistaken for heavy sleep or the effects of being drunk.

Other signs and symptoms of severe carbon monoxide poisoning include:

Prolonged exposure to carbon monoxide can lead to death due to suffocation in as short as a few hours. Because carbon monoxide can cause a fairly quick and unsuspecting death, it has been dubbed the silent killer.

Sources of carbon monoxide

Carbon monoxide is a byproduct of incomplete combustion, which often occurs when something burns with only a little bit of oxygen present. Carbon dioxide is let off by burning wood, coal, or trash, household appliances, certain paints, and motorized vehicles (e.g. cars, motorcycles). Even smoking cigarettes releases carbon monoxide, both for the smoker and as secondhand smoke.

Certain occupations, such as firefighters and vehicle mechanics, may be frequently exposed to carbon monoxide. It is important to wear the proper clothing and equipment if you expect to be exposed to carbon monoxide to prevent CO poisoning.

Many people have accidentally poisoned themselves doing simple things such as sitting in their car or garage while the engine is running or cooking without proper ventilation. They may mistake headaches from carbon monoxide exposure as normal occurrences, as their symptoms improve once they get away from the source of CO.

carbon monoxide poisoning

First aid treatment

If you or someone you know suddenly shows signs of carbon monoxide poisoning, it is important to get fresh air and find the source of the carbon monoxide. Open windows or doors to allow the carbon monoxide to dissipate from the area. Turn off appliances or put out any fires or gas stoves.

Severe carbon monoxide poisoning is considered a medical emergency, especially for children, the elderly, and those with pre-existing lung conditions. Contact your local emergency care services for treatment right away.

Aside from smoke detectors, carbon monoxide detectors in your home and workspaces can prevent accidental poisoning.

Key Takeaways

In summary, carbon monoxide poisoning is a silent killer. Despite being toxic, this gas is very common in the environment.

Household exposure is often due to cars, burning coal, wood, or trash, and gas stoves and appliances. Cigarette smoke also contains carbon monoxide, making smoking and secondhand smoke another source.

If you or someone you know is experiencing headaches, nausea, or loss of consciousness after exposure to any of these things, it may be due to carbon monoxide poisoning. Talk to a doctor or contact emergency services right away for treatment.

Learn more about First Aid here.

Hello Health Group does not provide medical advice, diagnosis or treatment.


Carbon Monoxide Poisoning: Pathogenesis, Management, and Future Directions of Therapy https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5363978/ Accessed May 19, 2021

Carbon Monoxide Poisoning FAQs https://www.cdc.gov/co/faqs.htm Accessed May 19, 2021

Carbon Monoxide Poisoning in Children https://www.stanfordchildrens.org/en/topic/default?id=carbon-monoxide-poisoning-in-children-90-P02835 Accessed May 19, 2021

Carbon Monoxide Poisoning https://www.osha.gov/sites/default/files/publications/carbonmonoxide-factsheet.pdf Accessed May 19, 2021

Carbon Monoxide Toxicity https://www.ncbi.nlm.nih.gov/books/NBK430740/ Accessed May 19, 2021

Carbon monoxide poisoning https://www.nhs.uk/conditions/carbon-monoxide-poisoning/ Accessed May 19, 2021

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Written by Stephanie Nicole Nera, RPh, PharmD Updated May 20