Table of ContentsView AllTable of ContentsTesting the Air for Carbon MonoxideDiagnosisFAQNext in Carbon Monoxide Poisoning GuideHow Carbon Monoxide Poisoning Is Treated
Table of ContentsView All
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Table of Contents
Testing the Air for Carbon Monoxide
Diagnosis
FAQ
Next in Carbon Monoxide Poisoning Guide
Testing for carbon monoxide (CO) includes testing the person exposed and determining whether there is carbon monoxide in the home or location where exposure occurred.
Methods for testing your home for carbon monoxide include having CO detectors installed and testing for combustion problems in heating systems.
This article discusses how to diagnose and test your home for carbon monoxide.
© Verywell, 2018
Carbon monoxide is in the fumes that can come from furnaces, vehicles, generators, stoves, lanterns, gas ranges, or burning charcoal or wood. CO can build up in enclosed or partially enclosed spaces like homes and garages. People and animals can be poisoned and can die from breathing CO.
CO Detectors
The easiest way to test for carbon monoxide inside your home is with a CO detector which also has an alarm. These devices are battery-operated. CO detectors should be tested monthly and batteries replaced at least once a year unless the device has a sealed 10-year battery. CO detectors should be installed on every level of the home and outside sleeping areas.
Electrical Combustion Testing Instrument
Diagnosing Carbon Monoxide Poisoning
There isn’t a self-diagnosis option for carbon monoxide poisoning. Symptoms may include:
The level of carbon monoxide increases as symptoms become more severe. The damage to the body is cumulative: If COHgb blood levels exceed 60%,hypotension(low blood pressure), coma, respiratory failure, and death may occur.
Call 911 if you observe confusion or a loss of consciousness.
You should suspect carbon monoxide poisoning if more than one person in a building with a combustion source (furnace, fireplace, gas appliances, wood-burning stove, etc.) is complaining of headaches and nausea.
If carbon monoxide poisoning is suspected, all occupants of a building should go outside to breathe fresh air, and 911 should be called. If you suspect CO poisoning, don’t try to drive; call an ambulance.
Carbon Monoxide in the Blood
Carbon monoxide (CO) binds to hemoglobin like oxygen does. A significant difference, however, is that hemoglobin has 230 times the affinity for CO than it does for oxygen. This means even a small amount of inhaled carbon monoxide will bind to hemoglobin, blocking out oxygen in the process.
Hemoglobin that is attached to CO is called carboxyhemoglobin (COHgb). Measurements of the amount of COHgb in the blood are used to detect carbon monoxide in the blood and determine the severity of CO poisoning.
As symptoms become more severe, the levels of carboxyhemoglobin (COHgb) increase in the blood.
First Responder Testing
Some first responders have the ability to measure carboxyhemoglobin in the blood using a device called a pulse carbon monoxide oximeter.The pulse CO-oximeter measures carbon monoxide saturation in the hemoglobin (SpCO). It uses light waves (usually shone through the fingertips) to measure carbon monoxide saturation noninvasively.
Another form of noninvasive measurement uses exhaled air to determine levels of carbon monoxide. Some research has found exhaled CO inaccurate as a determinant of carbon monoxide poisoning.
Laboratory Tests
In the hospital, a more invasive but more accurate test, called blood gas, is used.
Arterial blood gas tests are the standard for oxygen and carbon dioxide because those gases change significantly before and after blood flows through body tissues.
Blood gas tests are considered more accurate than pulse CO-oximetry.Even though oximetry is useful for identifying patients at the scene who potentially have carbon monoxide poisoning, blood gases should be obtained to confirm carboxyhemoglobin levels.
Imaging
Acute carbon monoxide poisoning that comes from high concentrations of carbon monoxide in relatively short periods of exposure is not the only effect of carbon monoxide exposure. Chronic (long-term) carbon monoxide exposure at much lower concentrations may cause tissue damage, especially to the heart and brain.
Even though the levels of carboxyhemoglobin in chronic exposure patients might be lower than in acute patients, there are other ways to identify damage. The most common is to look at the tissues through medical imaging.
Magnetic resonance imaging (MRI) is the best way to examine the brain for potential injury from carbon monoxide poisoning.
Differential Diagnoses
Due to the vagueness of most signs andsymptoms associated with carbon monoxide poisoning—nausea, vomiting, headache, fatigue, chest pain—other diagnoses are regularly suspected. A high concentration of carbon monoxide at a patient’s home will suggest the possibility of carbon monoxide poisoning, but other causes still have to be ruled out.
The list of differential diagnoses is too broad to identify. Each case is different and should be evaluated based on the patient’s presentation, history, and tests.
Summary
If carbon monoxide exposure or poisoning is suspected, immediately get out of the building and call 911 for assistance.
Frequently Asked Questions
You can’t self-diagnose CO poisoning, but some symptoms may include:Headache and nauseaMuscle weakness, dizziness, trouble concentrating, and impaired judgmentBe sure CO detectors are installed in your home and checked regularly to help prevent breathing in carbon monoxide.
You can’t self-diagnose CO poisoning, but some symptoms may include:
Be sure CO detectors are installed in your home and checked regularly to help prevent breathing in carbon monoxide.
Cyanide is a colorless gas that, when inhaled in large quantities, prevents cells in the body from using oxygen, much like carbon monoxide does. Cyanide poisoning is detected with blood and urine tests, and because it’s eliminated from the blood quickly, testing must be done right away.Cyanide poisoning may occur along with carbon monoxide poisoning in certain cases, such as a house fire, but is more challenging to diagnose.
Cyanide is a colorless gas that, when inhaled in large quantities, prevents cells in the body from using oxygen, much like carbon monoxide does. Cyanide poisoning is detected with blood and urine tests, and because it’s eliminated from the blood quickly, testing must be done right away.
Cyanide poisoning may occur along with carbon monoxide poisoning in certain cases, such as a house fire, but is more challenging to diagnose.
How Carbon Monoxide Poisoning Is Treated
8 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.U.S. Centers for Disease Control and Prevention.Carbon monoxide poisoning basics.U.S, Consumer Product Safety Commission.It’s time to change smoke and carbon monoxide alarm batteries.Merck Manual Professional Version.Carbon Monoxide Poisoning. Apr 2020.Rose JJ, Wang L, Xu Q, et al.Carbon monoxide poisoning: pathogenesis, management, and future directions of therapy.Am J Respir Crit Care Med. 2017;195(5):596-606. doi:10.1164/rccm.201606-1275CITownsend CL, Maynard RL.Effects on health of prolonged exposure to low concentrations of carbon monoxide.Occup Environ Med. 2002;59(10):708-11. doi:10.1136/oem.59.10.708U.S. Centers for Disease Control and Prevention.Clinical guidance for carbon monoxide poisoning following disasters and severe weather.National Library of Medicine StatPearls.Cyanide toxicity.Lawson-Smith P, Jansen EC, Hyldegaard O.Cyanide intoxication as part of smoke inhalation–a review on diagnosis and treatment from the emergency perspective.Scand J Trauma Resusc Emerg Med. 2011;19:14. doi:10.1186/1757-7241-19-14Additional ReadingMcKenzie, L. B., Roberts, K. J., Shields, W. C., McDonald, E., Omaki, E., Abdel-Rasoul, M., & Gielen, A. C. (2017).Distribution and Evaluation of a Carbon Monoxide Detector Intervention in Two Settings: Emergency Department and Urban Community.Journal of Environmental Health,79(9), 24–30.Cannon, C., Bilkowski, R., Adhikari, S., & Nasr, I. (2004).The correlation of carboxyhemoglobin levels between venous and arterial blood gas samples.Annals Of Emergency Medicine,44(4), S55. doi:10.1016/j.annemergmed.2004.07.181Hullin, T., Aboab, J., Desseaux, K., Chevret, S., & Annane, D. (2017).Correlation between clinical severity and different non-invasive measurements of carbon monoxide concentration: A population study.PLoS ONE,12(3), e0174672. http://doi.org/10.1371/journal.pone.0174672Kuroda, H., Fujihara, K., Kushimoto, S., & Aoki, M. (2015).Novel clinical grading of delayed neurologic sequelae after carbon monoxide poisoning and factors associated with outcome.Neurotoxicology,48, 35-43. doi:10.1016/j.neuro.2015.03.002Rose, J. J., Wang, L., Xu, Q., McTiernan, C. F., Shiva, S., Tejero, J., & Gladwin, M. T. (2017).Carbon Monoxide Poisoning: Pathogenesis, Management, and Future Directions of Therapy.American Journal of Respiratory and Critical Care Medicine,195(5), 596–606. http://doi.org/10.1164/rccm.201606-1275CI
8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.U.S. Centers for Disease Control and Prevention.Carbon monoxide poisoning basics.U.S, Consumer Product Safety Commission.It’s time to change smoke and carbon monoxide alarm batteries.Merck Manual Professional Version.Carbon Monoxide Poisoning. Apr 2020.Rose JJ, Wang L, Xu Q, et al.Carbon monoxide poisoning: pathogenesis, management, and future directions of therapy.Am J Respir Crit Care Med. 2017;195(5):596-606. doi:10.1164/rccm.201606-1275CITownsend CL, Maynard RL.Effects on health of prolonged exposure to low concentrations of carbon monoxide.Occup Environ Med. 2002;59(10):708-11. doi:10.1136/oem.59.10.708U.S. Centers for Disease Control and Prevention.Clinical guidance for carbon monoxide poisoning following disasters and severe weather.National Library of Medicine StatPearls.Cyanide toxicity.Lawson-Smith P, Jansen EC, Hyldegaard O.Cyanide intoxication as part of smoke inhalation–a review on diagnosis and treatment from the emergency perspective.Scand J Trauma Resusc Emerg Med. 2011;19:14. doi:10.1186/1757-7241-19-14Additional ReadingMcKenzie, L. B., Roberts, K. J., Shields, W. C., McDonald, E., Omaki, E., Abdel-Rasoul, M., & Gielen, A. C. (2017).Distribution and Evaluation of a Carbon Monoxide Detector Intervention in Two Settings: Emergency Department and Urban Community.Journal of Environmental Health,79(9), 24–30.Cannon, C., Bilkowski, R., Adhikari, S., & Nasr, I. (2004).The correlation of carboxyhemoglobin levels between venous and arterial blood gas samples.Annals Of Emergency Medicine,44(4), S55. doi:10.1016/j.annemergmed.2004.07.181Hullin, T., Aboab, J., Desseaux, K., Chevret, S., & Annane, D. (2017).Correlation between clinical severity and different non-invasive measurements of carbon monoxide concentration: A population study.PLoS ONE,12(3), e0174672. http://doi.org/10.1371/journal.pone.0174672Kuroda, H., Fujihara, K., Kushimoto, S., & Aoki, M. (2015).Novel clinical grading of delayed neurologic sequelae after carbon monoxide poisoning and factors associated with outcome.Neurotoxicology,48, 35-43. doi:10.1016/j.neuro.2015.03.002Rose, J. J., Wang, L., Xu, Q., McTiernan, C. F., Shiva, S., Tejero, J., & Gladwin, M. T. (2017).Carbon Monoxide Poisoning: Pathogenesis, Management, and Future Directions of Therapy.American Journal of Respiratory and Critical Care Medicine,195(5), 596–606. http://doi.org/10.1164/rccm.201606-1275CI
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
U.S. Centers for Disease Control and Prevention.Carbon monoxide poisoning basics.U.S, Consumer Product Safety Commission.It’s time to change smoke and carbon monoxide alarm batteries.Merck Manual Professional Version.Carbon Monoxide Poisoning. Apr 2020.Rose JJ, Wang L, Xu Q, et al.Carbon monoxide poisoning: pathogenesis, management, and future directions of therapy.Am J Respir Crit Care Med. 2017;195(5):596-606. doi:10.1164/rccm.201606-1275CITownsend CL, Maynard RL.Effects on health of prolonged exposure to low concentrations of carbon monoxide.Occup Environ Med. 2002;59(10):708-11. doi:10.1136/oem.59.10.708U.S. Centers for Disease Control and Prevention.Clinical guidance for carbon monoxide poisoning following disasters and severe weather.National Library of Medicine StatPearls.Cyanide toxicity.Lawson-Smith P, Jansen EC, Hyldegaard O.Cyanide intoxication as part of smoke inhalation–a review on diagnosis and treatment from the emergency perspective.Scand J Trauma Resusc Emerg Med. 2011;19:14. doi:10.1186/1757-7241-19-14
U.S. Centers for Disease Control and Prevention.Carbon monoxide poisoning basics.
U.S, Consumer Product Safety Commission.It’s time to change smoke and carbon monoxide alarm batteries.
Merck Manual Professional Version.Carbon Monoxide Poisoning. Apr 2020.
Rose JJ, Wang L, Xu Q, et al.Carbon monoxide poisoning: pathogenesis, management, and future directions of therapy.Am J Respir Crit Care Med. 2017;195(5):596-606. doi:10.1164/rccm.201606-1275CI
Townsend CL, Maynard RL.Effects on health of prolonged exposure to low concentrations of carbon monoxide.Occup Environ Med. 2002;59(10):708-11. doi:10.1136/oem.59.10.708
U.S. Centers for Disease Control and Prevention.Clinical guidance for carbon monoxide poisoning following disasters and severe weather.
National Library of Medicine StatPearls.Cyanide toxicity.
Lawson-Smith P, Jansen EC, Hyldegaard O.Cyanide intoxication as part of smoke inhalation–a review on diagnosis and treatment from the emergency perspective.Scand J Trauma Resusc Emerg Med. 2011;19:14. doi:10.1186/1757-7241-19-14
McKenzie, L. B., Roberts, K. J., Shields, W. C., McDonald, E., Omaki, E., Abdel-Rasoul, M., & Gielen, A. C. (2017).Distribution and Evaluation of a Carbon Monoxide Detector Intervention in Two Settings: Emergency Department and Urban Community.Journal of Environmental Health,79(9), 24–30.Cannon, C., Bilkowski, R., Adhikari, S., & Nasr, I. (2004).The correlation of carboxyhemoglobin levels between venous and arterial blood gas samples.Annals Of Emergency Medicine,44(4), S55. doi:10.1016/j.annemergmed.2004.07.181Hullin, T., Aboab, J., Desseaux, K., Chevret, S., & Annane, D. (2017).Correlation between clinical severity and different non-invasive measurements of carbon monoxide concentration: A population study.PLoS ONE,12(3), e0174672. http://doi.org/10.1371/journal.pone.0174672Kuroda, H., Fujihara, K., Kushimoto, S., & Aoki, M. (2015).Novel clinical grading of delayed neurologic sequelae after carbon monoxide poisoning and factors associated with outcome.Neurotoxicology,48, 35-43. doi:10.1016/j.neuro.2015.03.002Rose, J. J., Wang, L., Xu, Q., McTiernan, C. F., Shiva, S., Tejero, J., & Gladwin, M. T. (2017).Carbon Monoxide Poisoning: Pathogenesis, Management, and Future Directions of Therapy.American Journal of Respiratory and Critical Care Medicine,195(5), 596–606. http://doi.org/10.1164/rccm.201606-1275CI
McKenzie, L. B., Roberts, K. J., Shields, W. C., McDonald, E., Omaki, E., Abdel-Rasoul, M., & Gielen, A. C. (2017).Distribution and Evaluation of a Carbon Monoxide Detector Intervention in Two Settings: Emergency Department and Urban Community.Journal of Environmental Health,79(9), 24–30.
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