Carbon monoxide poisoning
Carbon monoxide is an odorless gas that causes thousands of deaths each year in North America. Breathing in carbon monoxide is very dangerous. It is the leading cause of poisoning death in the United States.
This article is for information only. DO NOT use it to treat or manage an actual poison exposure. If you or someone you are with has an exposure, call your local emergency number (such as 911), or your local poison center can be reached directly by calling the national toll-free Poison Help hotline (1-800-222-1222) from anywhere in the United States.
Carbon monoxide is a chemical produced from the incomplete burning of natural gas or other products containing carbon.
The following items may produce carbon monoxide:
- Anything that burns coal, gasoline, kerosene, oil, propane, or wood
- Automobile engines
- Charcoal grills (charcoal should never be burned indoors)
- Indoor and portable heating systems
Propane is a colorless and odorless flammable gas that can turn into liquid under very cold temperatures. This article discusses the harmful effects...
- Stoves (indoor and camp stoves)
- Water heaters that use natural gas
Note: This list may not be all inclusive.
When you breathe in carbon monoxide, the poison replaces the oxygen in your bloodstream. Your heart, brain, and body will become starved of oxygen.
Symptoms vary from person to person. Those at high risk include young children, the elderly, people with lung or heart disease, people who are at high altitudes, and smokers. Carbon monoxide can harm a fetus (unborn baby still in the womb).
Symptoms of carbon monoxide poisoning may include:
Breathing problems, including no breathing,
shortness of breath
Shortness of breath
Breathing difficulty may involve:Difficult breathingUncomfortable breathingFeeling like you are not getting enough air
Hyperventilation is rapid and deep breathing. It is also called overbreathing, and it may leave you feeling breathless.
(may occur suddenly in people with
Chest pain is discomfort or pain that you feel anywhere along the front of your body between your neck and upper abdomen.
Angina is a type of chest discomfort or pain due to poor blood flow through the blood vessels (coronary vessels) of the heart muscle (myocardium). Th...
Decreased alertness is a state of reduced awareness. A coma is a state of decreased alertness from which a person cannot be awakened. A long-term co...
Confusion is the inability to think as clearly or quickly as you normally do. You may feel disoriented and have difficulty paying attention, remembe...
A seizure is the physical findings or changes in behavior that occur after an episode of abnormal electrical activity in the brain. The term "seizure...
Fainting is a brief loss of consciousness due to a drop in blood flow to the brain. The episode most often lasts less than a couple of minutes and y...
- General weakness and achiness
A headache is pain or discomfort in the head, scalp, or neck. Serious causes of headaches are rare. Most people with headaches can feel much better...
Hyperactivity means having increased movement, impulsive actions, and a shorter attention span, and being easily distracted.
- Impaired judgment
- Low blood pressure
- Muscle weakness
- Rapid or abnormal heartbeat
Shock is a life-threatening condition that occurs when the body is not getting enough blood flow. Lack of blood flow means that the cells and organs...
Nausea and vomiting
Nausea and vomiting
Nausea is feeling an urge to vomit. It is often called "being sick to your stomach. "Vomiting or throwing-up is forcing the contents of the stomach ...
Unconsciousness is when a person is unable to respond to people and activities. Doctors often call this a coma or being in a comatose state. Other c...
Animals can also be poisoned by carbon monoxide. People who have pets at home may notice that their animals become weak or unresponsive from carbon monoxide exposure. Often the pets will get sick before humans.
If the person breathed in the poison, immediately move him or her to fresh air. Seek immediate medical help.
Install a carbon monoxide detector on each floor of your home. Place an additional detector near any major gas-burning appliances (such as a furnace or water heater).
Many carbon monoxide poisonings occur in the winter months when furnaces, gas fireplaces, and portable heaters are being used and windows are closed. Have heaters and gas-burning appliances regularly inspected to make sure they are safe to use.
Before Calling Emergency
The following information is helpful for emergency assistance:
- Person's age, weight, and condition (for example, is the person awake or alert?)
- How long they may have been exposed to the carbon monoxide, if known
However, DO NOT delay calling for help if this information is not immediately available.
Your local poison center can be reached directly by calling the national toll-free Poison Help hotline (1-800-222-1222) from anywhere in the United States. They will give you further instructions.
Poison Help hotline
For a POISON EMERGENCY call:1-800-222-1222ANYWHERE IN THE UNITED STATESThis national hotline number will let you talk to experts in poisoning. This ...
This is a free and confidential service. All local poison control centers in the United States use this national number. You should call if you have any questions about poisoning or poison prevention. You can call 24 hours a day, 7 days a week.
What to Expect at the Emergency Room
The health care provider will measure and monitor the person's vital signs, including temperature, pulse, breathing rate, and blood pressure. The person may receive:
- Airway support, including oxygen, breathing tube through the mouth (intubation), and breathing machine (ventilator)
- Blood and urine tests
- Chest x-ray
- EKG (electrocardiogram, or heart tracing)
- Fluids through a vein (intravenous or IV)
Hyperbaric oxygen therapy
(high-pressure oxygen given in a special chamber)
Hyperbaric oxygen therapy
Hyperbaric oxygen therapy uses a special pressure chamber to increase the amount of oxygen in the blood.
- Medicines to treat symptoms
Carbon monoxide poisoning can cause death. For those who survive, recovery is slow. How well a person does depends on the amount and length of exposure to the carbon monoxide. Permanent brain damage may occur.
If the person still has impaired mental ability after 2 weeks, the chance of a complete recovery is not very good. Impaired mental ability can reappear after a person has been symptom-free for 1 to 2 weeks.
Kao LW. Toxicity associated with carbon monoxide. Clin Lab Med . 2006;26(1):99-125. PMID: 16567227 www.ncbi.nlm.nih.gov/pubmed/16567227 .
Nelson LS, Hoffman RS. Inhaled toxins. In: Marx JA, Hockberger RS, Walls RM, et al., eds. Rosen's Emergency Medicine: Concepts and Clinical Practice . 8th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 159.
Sather JE, Tantawy H. Toxins. Anesthesiol Clin North America . 2006;24(3):647-70. PMID: 17240611 www.ncbi.nlm.nih.gov/pubmed/17240611 .
Review Date: 1/25/2015
Reviewed By: Jacob L. Heller, MD, MHA, Emergency Medicine, Virginia Mason Medical Center, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.