Carbon monoxide, also called CO, is a poisonous gas. It has no odor, no taste, and no color . Carbon monoxide poisoning is a life-threatening condition caused by inhaling too much CO.

What is going on in the body?

CO is produced when a fuel is burned. Fuels include gas, oil, kerosene, charcoal, or wood. CO may be found in a number of items that people come in contact with each day. These include:

If fresh air is limited and CO is released in the air, it can reach a dangerously high level. When CO is inhaled, it enters the bloodstream and attaches to a blood cell protein called hemoglobin. Hemoglobin helps blood cells carry oxygen from the lungs to the rest of the body. If CO attaches to hemoglobin, the blood cells can't carry oxygen. The body then can't function in a healthy way.

What are the causes and risks of the condition?

CO poisoning can occur when small amounts of CO are inhaled over a long time. It can also occur when large amounts of CO are absorbed over a short time, especially in a closed setting such as a garage or car.