Carbon Monoxide Poisoning

More than one third of carbon monoxide deaths occur when the victim is asleep

Carbon monoxide (CO) is a tasteless, colourless, odourless and highly poisonous gas produced during incomplete combustion. It is found in automobile exhaust fumes, faulty stoves and heating systems, fire and cigarette smoke.

Other sources of CO include wood burning stoves, kerosene heaters, lanterns, grills and improperly ventilated water heaters and gas stoves.

CO poisoning is a potentially fatal condition that occurs when carbon monoxide gas is inhaled. It can cause sudden medical problems. In severe cases, it can lead to chronic and persistent mental and physical defects and even death.

CO poisoning usually occurs in an enclosed space and when ventilation is poor.

CO can be lethal as it interferes with the blood’s ability to carry oxygen and the cells’ internal chemical reactions. Once inhaled, the gas travels into the bloodstream where it attaches itself to the red blood cells that normally transmit oxygen.

If exposure to CO continues, your blood will gradually lose its ability to carry sufficient oxygen to meet the body’s requirements. Without sufficient oxygen, individual cells in vital organs such as the brain and heart suffocate and die.


Signs and symptoms of CO poisoning vary depending on the concentration of the gas in the environment and the duration of the exposure. Common symptoms include:

  • Headaches
  • Fatigue
  • Shortness of breath
  • Dizziness
  • Clumsiness or difficulty walking
  • Chest pains
  • Vision problems

Exposure to CO over the duration of a few weeks or months may cause flu-like symptoms with ongoing headaches, fatigue and nausea.

People who suffer from long-term exposure to low levels of CO may experience numbness, unexplained vision problems, impaired memory and concentration difficulties.

Exposure to CO may also lead to long-term complications such as neurological problems. These range from mild to severe intellectual impairment, blindness and deafness. Among pregnant women, poisoning can cause fetal death or cerebral palsy in a baby.


Here’s what you need to do to help prevent CO poisoning and reduce your risk of exposure:

  • Never leave your car running in a closed space. When the car idles outdoors, leave the windows slightly open for ventilation.
  • Never use charcoal grills indoors
  • Have fuel-burning appliances professionally installed. After installation, periodically check the vents for blockages or cracks.


Seek medical treatment if you or someone around you appears to be suffering from CO poisoning. Firstly, a doctor needs to know the duration of your exposure to CO. If you have mild CO poisoning, you will receive several hours of oxygen therapy.

If you have severe poisoning and have fallen unconscious, you will be connected to a respirator and may be placed in a hyperbaric oxygen chamber.

A doctor may conduct a blood test to confirm the diagnosis and to determine the levels of oxygen and carboxyhemoglobin (CO attached to haemoglobin). Depending on the symptoms, additional tests such as an electrocardiogram (ECG) may be conducted to evaluate symptoms of chest pain or irregular heartbeat.

In people with neurological symptoms, a Magnetic Resonance Imaging (MRI) or Computed Tomography (CT) scan of the brain may be needed.

If you are pregnant and have been exposed to CO, seek medical attention immediately.

If you suspect that a person is suffering from carbon monoxide poisoning, move them into the open air as quickly as possible. Also, turn off burning appliances or furnaces and open all windows to clear the air.

Call for medical help immediately and while you wait, check for respiration and pulse. If both are absent, begin CPR. If breathing is absent but there is a pulse, start mouth-to-mouth resuscitation and continue until the victim begins breathing or help arrives.



  • Open windows while cooking
  • Maintain your car engine regularly
  • Maintain your fuel burning appliances so they are in good working order


  • Modify your vehicle exhaust system
  • Sleep in the car with the engine running
  • Leave anyone in a closed, parked car with the engine running

Comments are closed.