Carbon Monoxide - Health Impact

Because CO is odorless, colorless, and otherwise undetectable to the human senses, people may not know that they are being exposed. The initial symptoms of low to moderate CO poisoning are similar to the flu (but without the fever). Initial symptoms include:

Headache
Fatigue
Shortness of breath
Nausea
Dizziness

(Image credit: sf-fire.org)

High level CO poisoning results in progressively more severe symptoms, including:

Mental confusion
Vomiting
Loss of muscular coordination
Loss of consciousness
Ultimately death

Symptom severity is related to both the CO level and the duration of exposure. For slowly developing residential CO problems, occupants and/or physicians can mistake mild to moderate CO poisoning symptoms for the flu, which sometimes results in tragic deaths. For rapidly developing, high level CO exposures (e.g., associated with use of generators in residential spaces), victims can rapidly become mentally confused, and can lose muscle control without having first experienced milder symptoms; they will likely die if not rescued.