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Carbon Monoxide Exposure

What is carbon monoxide exposure?

Carbon monoxide (CO) is a poisonous gas that you cannot see, taste, or smell. Carbon monoxide exposure happens when you breathe in CO gas. You can be poisoned by exposure to high levels of CO. Patients with mild poisoning usually recover completely with oxygen treatment. Severe poisoning can cause permanent brain injury or be life-threatening.

Where is CO found?

CO may come from any of the following sources:

  • Smoke from a fire: This includes building fires.

  • Faulty devices or equipment: These include furnaces, water heaters, gas stoves, and wood-burning stoves or fireplaces.

  • Gas powered tools, vehicles, or machines: CO exposure happens when gas powered tools are used in poorly ventilated areas. Some examples are barbecue grills, lawn mowers, and generators. Chain saws, fork lifts, and tractors can also cause CO exposure if you use them in poorly ventilated areas.

  • Nonvented devices: Nonvented propane heaters, stoves, grills, or lanterns used inside a house, trailer, or tent can cause CO exposure.

  • Motor vehicles: The exhaust of from cars can cause CO exposure.

Who is at increased risk of CO poisoning?

  • Babies: Babies need more oxygen than adults. They breathe faster and may breathe in more CO. Unborn babies are especially at risk of CO poisoning.

  • Older adults: As you get older, your body has more difficulty with CO. You may also have a medical condition that is made worse by CO exposure.

  • Persons with a medical condition: Heart disease, blood vessel disease, sickle cell anemia, and lung problems increase your risk for CO poisoning.

  • Pregnant women: You may breathe faster during pregnancy. This causes you to breathe in more CO.

  • Smokers: You normally breathe in small amounts of CO from the smoke. This increases the amount of CO in your body, so you are at higher risk of CO poisoning if you are exposed to another source of CO.

  • Certain workers: If you work in construction or agriculture, you are more likely to be around equipment or chemicals that produce CO.

What are the signs and symptoms of CO poisoning?

  • Immediate signs and symptoms: You may have any of the following right after you are exposed to CO:

    • Blurred vision, dizziness, or a headache

    • Nausea or vomiting

    • Faster breathing than normal, or trouble breathing

    • Weakness or muscle pain

    • Dark or red urine

    • Chest pain, or a fast, strong, or irregular heartbeat

    • Confusion, fainting, or seizures

  • Late signs and symptoms: These may be temporary or permanent. You may have any of the following, 2 to 40 days after you are exposed to CO:

    • Changes in behavior

    • Increased anxiety or depression

    • Tremors or shaking of your fingers or hands

    • Trouble controlling urine or bowel movements

    • Trouble thinking clearly or learning new things

    • Trouble moving, bending your arms or legs, or walking

    • Difficulty speaking, chewing, or controlling facial muscles

How is CO poisoning diagnosed?

Your caregiver will examine you and ask about your symptoms. Tell him if anyone you live or work with has similar signs and symptoms, including pets. Tell him if you use home heating devices that burn gas, oil, wood, or other fuel. He may need to know if you have used gas-powered tools, paints, or varnishes recently. You may also need more than one of the following:

  • Neurologic exam: This can show how well your brain works after CO exposure. Caregivers will check your pupils, memory, hand grasp, and balance.

  • Blood gases: This is a blood test that checks the amount of oxygen and carbon dioxide in your blood. It can tell how much CO you have been exposed to.

  • Blood tests: These check your overall health and check for other problems that CO poisoning may cause.

  • Breath analyzer: This device measures the amount of carbon monoxide in your breath. You will hold your breath for 15 seconds and then breathe out into the device.

  • Telemetry is continuous monitoring of your heart rhythm. Sticky pads placed on your skin connect to an EKG machine that records your heart rhythm.

How is CO poisoning treated?

You may need more than one of the following:

  • You may need extra oxygen if your blood oxygen level is lower than it should be. You may get oxygen through a mask placed over your nose and mouth or through small tubes placed in your nostrils. Ask your healthcare provider before you take off the mask or oxygen tubing.

  • Hyperbaric oxygen therapy: This is used to get more oxygen into your body. The oxygen is given under pressure to help it get into your tissues and blood. You remain in a room called a hyperbaric chamber during the treatment.

  • Endotracheal (ET) tube: An endotracheal tube may be put into your mouth or nose. It goes down into your windpipe to help keep your airway open and help you breathe. It may be hooked to a ventilator (breathing machine), and you may get extra oxygen through your ET tube. You will not be able to talk while the ET tube is in place.

  • IV therapy: Liquids are given through an IV to increase your body fluids and blood pressure.

What are the risks of CO poisoning?

  • Hyperbaric oxygen treatment may cause ear pain, hearing and eyesight problems, coughing, and chest tightness. Treatment can also cause seizures and lung problems. Even with treatment, your signs and symptoms may come back. You may have trouble thinking or remembering things, tremors or shaking, depression, or anxiety.

  • Without treatment, your signs and symptoms may become life-threatening. You may develop heart, lung, or brain problems. Your kidneys may stop working, or you may go into a coma or have a heart attack.

How can I prevent CO poisoning?

  • Install a CO detector in your sleeping area. Place it 5 feet above the floor and away from fireplaces or gas-burning equipment.

  • Check your chimney, furnace, or wood stove. Check for problems every year before you use them. Have your fireplace flue cleaned on a regular basis.

  • Do not use your gas kitchen oven to heat your home.

  • Do not use barbecues or heaters that burn fuel inside your home or other closed spaces.

  • Do not let motor vehicles run in closed areas. This includes letting your car run in a garage. If the car is outside, check that the exhaust pipe is not blocked. Make sure there is good air flow around you if you must stand near vehicle or equipment exhaust.

Where can I find more information?

  • American Association of Poison Control Centers
    3201 New Mexico Avenue, Suite 330
    Washington , DC 20016
    Phone: 1- 202 - 3627217
    Web Address:
  • Environmental Protection Agency
    Office of Radiation and Indoor Air Indoor Environments Division
    1200 Pennsylvania Avenue, NW Mail Code 6609J
    Washington , DC 20460
    Phone: 1- 202 -
    Web Address:

When should I contact my caregiver?

Contact your caregiver if:

  • You feel dizzy.

  • You have a headache or start to vomit.

  • Your eyesight becomes blurred.

  • You have questions or concerns about your condition or care.

When should I seek immediate care?

Seek care immediately or call 911 if:

  • You have chest pain or an irregular or fast heartbeat.

  • You have trouble breathing or need to breathe faster than normal.

  • You faint or have a seizure.

  • You feel weak, have trouble moving, or have severe muscle pain.

  • Your urine becomes dark or red.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your caregivers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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