How does carbon monoxide poisoning occur?

Q. How does carbon monoxide poisoning occur?

A. As winter descends, cases of accidental carbon monoxide poisoning rise. The colorless, odorless gas is found in car exhaust and in fumes from fuel-burning appliances such as generators, charcoal grills, gas stoves, and wood fireplaces. It’s poisonous because it binds to hemoglobin, the protein in red blood cells that carries oxygen throughout your body. “The red blood cells pick up carbon monoxide quicker than they pick up oxygen,” which starves the body of oxygen, says Adina Sheroff, poison information specialist at the Regional Center for Poison Control and Prevention at Boston Children’s Hospital.

Symptoms depend on how much carbon monoxide is present and how long a person is exposed, explains Christopher Rosenbaum, an emergency medicine physician at Newton-Wellesley Hospital. At low levels, he says, people “just feel like they might be ill; it’s very vague and nondescript.” Typical complaints are flulike symptoms, headaches, dizziness, confusion, chest pain, and nausea. Rosenbaum often suspects carbon monoxide exposure if a patient feels better after changing locations or if someone else in the house has symptoms. Higher exposures can cause fainting, loss of consciousness, permanent brain or heart damage, and death.

To prevent exposure, properly vent and maintain gas appliances, furnaces, and fireplaces, and don’t run cars, fuel-burning grills, or generators in enclosed spaces. The only way to detect the gas is by installing working carbon monoxide detectors throughout a building. If a detector goes off or you suspect exposure, leave the area immediately and seek medical treatment.