If you're brought to an emergency room with suspected carbon monoxide poisoning, you may begin treatment immediately. To confirm your diagnosis, the doctor may test a sample of your blood for carbon monoxide.


Get into fresh air immediately and call 911 or emergency medical help if you or someone you're with develops signs or symptoms of carbon monoxide poisoning. These include headache, dizziness, nausea, shortness of breath, weakness and confusion.

Once you're at the hospital, treatment may involve:

  • Breathing pure oxygen. In the emergency room, you may breathe pure oxygen through a mask placed over your nose and mouth. This helps oxygen reach your organs and tissues. If you can't breathe on your own, a machine (ventilator) may do the breathing for you.
  • Spending time in a pressurized oxygen chamber. In many cases, hyperbaric oxygen therapy is recommended. This therapy involves breathing pure oxygen in a chamber in which the air pressure is about two to three times higher than normal. This speeds the replacement of carbon monoxide with oxygen in your blood.

    Hyperbaric oxygen therapy may be used in cases of severe carbon monoxide poisoning. It helps protect heart and brain tissue, which are particularly vulnerable to injury from carbon monoxide poisoning. Hyperbaric oxygen therapy may also be recommended for pregnant women because unborn babies are more susceptible to damage from carbon monoxide poisoning.

Preparing for your appointment

If you or someone you're with develops signs or symptoms of carbon monoxide poisoning — headache, dizziness, nausea, shortness of breath, weakness, confusion — get into fresh air immediately and call 911 or emergency medical help.

Hospital staff will need critical information as soon as you arrive. On the way to the hospital, try to prepare to answer questions about:

  • Possible sources of carbon monoxide exposure
  • Signs or symptoms, and when they started
  • Any mental impairment, including confusion and memory problems
  • Any loss of consciousness
  • Other medical conditions with which the affected person has been diagnosed, including pregnancy
  • Smoking habits
Oct. 16, 2019
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  2. Carbon monoxide poisoning — Prevention guidance. Centers for Disease Control and Prevention. https://www.cdc.gov/co/guidelines.htm. Accessed Feb. 17, 2018.
  3. Ferri FF. Carbon monoxide poisoning. In: Ferri's Clinical Advisor 2018. Philadelphia, Pa.: Elsevier; 2018. https://www.clinicalkey.com. Accessed Feb. 17, 2018.
  4. AskMayoExpert. Hyperbaric oxygen therapy. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2017.
  5. Clardy PF, et al. Carbon monoxide poisoning. https://www.uptodate.com/contents/search. Accessed Feb. 17, 2018.
  6. Toups GN (expert opinion). Mayo Clinic, Rochester, Minn. March 6, 2018.
  7. Toxic substances portal — Methylene chloride. Agency for Toxic Substances and Disease Registry. https://www.atsdr.cdc.gov/mmg/mmg.asp?id=230&tid=42. Accessed March 17, 2018.
  8. Palmer J, et al. Carbon monoxide poisoning and pregnancy: Critical nursing interventions. Journal of Emergency Nursing. 2015;41:479.
  9. What you should know about using paint strippers. U.S. Consumer Product Safety Commission. https://www.cpsc.gov/ko/content/what-you-should-know-about-using-paint-strippers. Accessed March 17, 2018.


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Carbon monoxide poisoning