Carbon Monoxide Poisoning Treatment

Medically Reviewed by Poonam Sachdev on February 06, 2024
5 min read

Carbon monoxide is a gas that you can't smell, taste, or see. It is produced from burning fuels including natural gas, coal, kerosene, wood, propane, and oil, and is present in engine exhaust. When this gas is present in large amounts, especially in confined spaces, carbon monoxide replaces the oxygen in your red blood cells, which leads to carbon monoxide poisoning. Carbon monoxide poisoning can cause serious bodily harm or even death.

Carbon monoxide levels

A carbon monoxide (CO) blood test shows how much of the gas is found in your blood. The test measures carboxyhemoglobin, which is produced when your blood mixes with carbon monoxide. Interpreting your test results depends on your gender, age, medical history, and other factors. Your doctor will be able to explain them to you.

Normal ranges (the percentage of CO in your blood):

  • Newborns: 10%-12%
  • Nonsmoking adults: less than 2%
  • Smoking adults: 4%-5%
  • Heavy smoking adults (more than two packs per day): 6%-8%

Higher levels can mean carbon monoxide illness or poisoning.

In well-ventilated spaces, carbon monoxide isn't usually a cause for concern. When CO is present in large amounts in relatively airtight spaces, it can accumulate and become dangerous to you quickly.

Carbon monoxide poisoning

Indoor garages can be particularly dangerous. Don't leave your car running in the garage, even if the garage door is fully open.

Other potential sources of dangerous carbon monoxide emissions include:

  • Faulty gas stoves and appliances such as clothes dryers, space heaters, or fireplaces
  • Wood-burning fireplaces
  • Faulty water heaters
  • Old or faulty furnaces that burn gas, oil, coal, or wood
  • Clogged chimneys
  • Outdoor fuel-burning or gas-powered appliances used indoors
  • Fire

How long does carbon monoxide poisoning take?

It can take up to 2 hours to show symptoms of carbon monoxide poisoning at low exposure levels. At higher levels, the process can take about 5 minutes.

If you inhale too much carbon monoxide, it builds up in your bloodstream, where it takes the place of the oxygen that belongs there. When your heart, brain, or other vital organs are deprived of that oxygen, you’re in trouble.

If the dangerous gas is getting into your system, you might:

  • Feel short of breath
  • Get dizzy
  • Become nauseous
  • Get a headache
  • Feel confused

Carbon monoxide is especially dangerous for infants, those who are pregnant, and people with ailments such as emphysema (which damages the air sacs in your lungs), asthma, or heart disease. Smaller amounts of the fumes can hurt them.

Long-term effects of carbon monoxide poisoning

It's critical to treat carbon monoxide poisoning quickly. Timely treatment may reverse harmful side effects. Depending on how long you were exposed and how much carbon monoxide you took in, you may have long-term health issues such as:

  • Breathing problems 
  • Parkinson's disease
  • Memory loss
  • Permanent brain damage
  • Heart damage

Get the person to fresh air

  • Move the person away from the area exposed to carbon monoxide.
  • If the person is unconscious, check for injuries before moving.
  • Turn off the source of carbon monoxide if you can do so safely.

Call 911

Begin cardiopulmonary resuscitation (CPR), if necessary

If the person is unresponsive, breathing abnormally, or not breathing:

  • Perform CPR for 1 minute before calling 911 if you are alone. Otherwise, have someone else call and begin CPR.
  • For a child, start CPR for children.
  • Continue CPR until the person begins breathing or emergency help arrives.


Carbon monoxide poisoning is treated with 100% oxygen to reintroduce oxygen into your blood cells. Depending on the severity of your exposure, the oxygen is delivered in different ways.

  • Mild poisoning is treated with oxygen delivered by a mask.
  • Severe carbon monoxide poisoning may require placing the person in a full-body, high-pressure chamber to help force oxygen into the body.

How long does carbon monoxide poisoning last?

With mild exposure, the effects may begin to wear off as soon as you inhale fresh air or pure oxygen. It may take up to a day for the carbon monoxide to completely leave your body. You might still feel symptoms until it clears or for up to 2 weeks after your carbon monoxide poisoning.

When you buy appliances that burn fuel, look for the seal of a testing agency such as UL. In your home, any equipment should be installed with vents running outdoors.

Here are more tips:

  • Maintenance. Have a qualified technician inspect your heating system, water heater, and any other fuel-burning appliances every year. If you have a fireplace, the chimney needs a going-over.

  • Emergency generators. Don’t use them in your garage or basement. Put them outside the house at least 20 feet from windows or doors.

  • Charcoal grills and portable camp stoves. Use them only outdoors.

  • Space heaters. Use them only when someone is awake to keep an eye on them; make sure there is some airflow in and out of the room. Don’t try to use a gas oven for heat.

  • Vehicles. Have your car or truck’s exhaust system checked each year. If your garage is attached to your home, don’t leave a vehicle running there. Even with the garage door open, the fumes can seep inside the house. If your vehicle has a tailgate, be sure to open windows anytime you drive with the tailgate down. If you don’t, carbon monoxide can be sucked into the vehicle.

Carbon monoxide detector

The U.S. Consumer Product Safety Commission recommends carbon monoxide detectors on every level of your home.

These detectors are available at hardware stores and other retailers. Buy alarms that are certified by a testing laboratory. The alarms can be battery-powered or hardwired. Plug-in and freestanding CO detectors are also available.

Follow the instructions about installation and change the batteries twice a year when the time changes.

Here are a few other guidelines:

  • If you can, place CO detectors outside each sleeping area.
  • Test the alarms once a month. Some alarms also give off audible signals on their own if the battery runs low or they break down.
  • If you have multiple alarms, connect them. That way, if one detects trouble, they all go off.
  • Before there’s any trouble, ask your fire department for the number to call if the alarm goes off.
  • Don't "borrow" batteries from your CO detector; keep it functioning.
  • If you have a boat or motor home, make sure detectors are also available there.
  • You might want to consider portable CO detector options for when you travel.

Signs something is wrong

By keeping your eyes open, you may spot evidence that appliances are out of whack or something else is wrong. A few danger signals:

  • Soot falling from fireplaces or appliances
  • Rust or water streaks on vents
  • Loose or disconnected vent pipes
  • Moisture inside windows
  • Cracked or crumbling masonry on a chimney

If you see any of these, have a trained technician check them out and fix any issues promptly.