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Carbon Monoxide Poisoning

  • Debra Wood, RN
Publication Type:


Carbon Monoxide Poisoning


Carbon monoxide poisoning can be fatal. It happens after inhaling carbon monoxide (CO) gas. CO is an odorless, tasteless and colorless gas. It can be easily inhaled without anyone knowing about it. This gas is released when gas, wood, coal or other fuels are burned.

Carbon Monoxide Binding to Hemoglobin.

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Carbon monoxide poisoning is caused by inhaling CO gas. Exposure can happen when any gas appliance is faulty or poorly ventilated such as:

  • A hole in ventilation pipes
  • Motor vehicle engines that are left running inside an enclosed garage
  • Barbecue grills, gas grills, or camp stoves used inside the home, garage, or basement
  • Power generators used inside the home, garage, or basement

CO is easily absorbed through the lungs. It binds to things in the blood and takes the place of the oxygen. The body does not get enough oxygen to function. Brain cells are at highest risk of damage.

Risk Factors

Carbon monoxide poisoning is more common men. Other things that may raise the risk include:

  • Alcohol or drug use
  • Cold weather
  • Having a heart or lung condition
  • Exposure to faulty appliances or ventilation
  • Fires in buildings or fireplaces
  • Waterpipe (hookah, narghile) use—for smoking tobacco or herbal products


Symptoms related to carbon monoxide poisoning are usually vague. They can be split into acute (immediate) and chronic symptoms.


The doctor will ask about symptoms and past health. A physical exam will be done. Tests may include:

  • Blood tests—to measure
    • Carboxyhemoglobin test—to show severity of exposure and track treatment progress
    • Oxygen levels
    • Electrolytes
  • Chest x-ray—to see if pneumonia is present
  • Electrocardiogram (EKG)—to check the heart's electrical activity and look for signs of heart damage


The first treatment is getting away from the source of the carbon monoxide. Breathing fresh air outdoors can help. Mild symptoms often improve after getting away from the gas.

The person will need care at the closest emergency room. The doctor will give oxygen until symptoms go away and carbon monoxide levels in the blood drop.

Other therapies may include:

  • Ventilator—to assist in breathing for people in a coma, or who have serious heart or nerve problems
  • Hyperbaric oxygen therapy —a special chamber in which oxygen is given under greater pressure than normal


CO has no odor or color, so people do not know if it is present. The following can reduce the risk of exposure:

  • Have an expert check the fireplace, chimney, and furnace every year. Debris can block vents and cause a build-up of carbon monoxide.
  • Have a professional check gas and kerosene appliances before heating season.
  • Make sure all gas and combustion appliances are vented to the outdoors. Check ventilation pipes for holes.
  • Do not use a gas stove or oven to heat the house.
  • Do not use a barbecue grill, camp stove, or unvented kerosene heater inside a house or tent.
  • Do not use generators or other gasoline-powered engines indoors.
  • Choose equipment that carries the seal of the American Gas Association or the Underwriters' Laboratory.
  • Install a carbon monoxide detector. Follow manufacturer's directions for installation and maintenance. Only use detector as a backup, in addition to other safety steps.
  • Have the car's exhaust system checked every year.
  • Do not run the car in the garage, especially with the door closed. Start the car and take it outside.
  • Do not leave the door from the garage to the house open when the car engine is running.

Acute Symptoms

  • Shortness of breath
  • Wheezing
  • Cough
  • Hoarse voice

Chronic Symptoms

  • Racing heartbeats
  • Chest pain
  • Nausea or vomiting
  • Headache
  • Numbness and tingling
  • Vision problems
  • Loss of appetite
  • Sleep problems
  • Dizziness
  • Tiredness
  • Memory loss
  • Reduced sex drive




  • Indoor air quality. Environmental Protection Agency website. Available at: https://www.epa.gov/indoor-air-quality-iaq.
  • Carbon monoxide poisoning. Centers for Disease Control and Prevention website. Available at: https://www.cdc.gov/co/default.htm.
  • Carbon monoxide toxicity. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/carbon-monoxide-toxicity.
  • Waterpipe tobacco smoking: health effects, research needs and recommended actions by regulators. World Health Organization website. Available at: https://www.who.int/publications/i/item/advisory-note-waterpipe-tobacco-smoking-health-effects-research-needs-and-recommended-actions-by-regulators-2nd-ed.
  • Weaver LK. Carbon monoxide poisoning. Undersea Hyperb Med. 2020;47(1):151-169.


  • April Scott, NP
Last Updated:

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.