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Signs of Mild Carbon Monoxide Poisoning

Carbon monoxide is a colorless, odorless, flammable, and highly toxic gas (CO = carbon+oxygen atoms), formed by an incomplete combustion of carbon. Because you can not see or smell it, it is potentially a silent killer; many people die per year from accidental carbon monoxide poisoning. Since signs of mild CO poisoning is non-specific, it gets passed for the common cold, flu, or symptoms of food poisoning. In addition, there is no fever connected with mild carbon monoxide poisoning.

Carbon monoxide can come from any source that burns fuel: motor vehicles, boats, generators, gas heaters, fireplaces,etc. When you breathe it in, it starts to replace the oxygen in your blood. If you take in too much, it CO can be deadly within minutes. Without proper oxygen, cells begin to die and organs stop working.

To be prudent, you should never sit in an idling car, even with the garage door opened. The gas can build up in the garage and leak back into the house. Along the same vein, swimming behind an idling boat is also dangerous. Any heating or cooking system that uses gas, oil, kerosene, wood, or charcoal is suspect, so it is important these appliances be inspected on a yearly basis. Appliances not properly installed, blocked chimneys, tightly enclosed areas can enable the build-up of carbon monoxide. Newer houses with well-insulated and tightly sealed walls can also trap CO inside. Symptoms can also be seasonal, headaches occurring during the winter when indoor heating is used more frequently.

Carbon monoxide poisoning can occur suddenly or over a period of time. Breathing low levels of CO long-term can cause severe heart problems and brain damage. You should see a doctor if you frequently experience mild headaches or nausea while indoors, as well as being short of breath. If symptoms get better when you leave the house, it may be mild CO poisoning. If other people in your family or co-workers are having similar symptoms within the building, it may also point mild CO poisoning.

Signs of carbon monoxide poisoning include headache, nausea, and dizziness. Some symptoms may manifest a few days or even a few months after exposure to CO. These may be confusion, loss of memory, or problems with coordination. Children generally have symptoms similar to stomach upset: nausea and vomiting. If levels build up in the body, symptoms worsen to include drowsiness and confusion; fast breathing/fast heartbeat/chest pain; hyperventilation; vision problems; even seizure. If you suspect CO poisoning, immediately call 911 and leave the premises, as you may pass out from inhalation or die if you keep breathing in fumes.

Carbon monoxide poisoning can be diagnosed with a blood test to determine CO levels. Treatment usually involves the patient being away from the toxic source of gas, providing basic life support as needed, being given oxygen before being taken to the hospital. While in hospital, best treatment for people with CO poisoning is to breathe oxygen through a mask or being inside an oxygen chamber, as this treatment will quickly reduce carbon monoxide levels. While people with mild poisoning can expect full recovery within time, 10-50% of people with severe CO poisoning may suffer long-term problems. These problems can show up as changes in coordination, vision, or behavior, and that can occur weeks after having had oxygen therapy.


* Never leave a car running in the garage, even if the door is opened.

* Do not swim behind an idling boat.

* Never use a gas or charcoal grill indoors, nor a gas oven for heating purposes.

* Do not use kerosene or propane heaters in an enclosed area such as tents, campers, trailers or motor homes.

* Do not use gas-powered generators, lawn mowers or engines in an enclosed area.

* Do not close the flue to a fireplace or a stove damper before a fire is completely out. It may become a silent killer.

For added peace of mind, invest in a properly installed CO alarm and know what to do if it sounds. Get one that is Underwriters Laboratory endorsed (UL).

Many people die each year from accidental carbon monoxide poisoning. Knowing the mild signs of poisoning many save your life.