Carbon Monoxide Poisoning

Common Symptoms:

Making a diagnosis of CO poisoning is crucial, as acute high level CO poisoning can be fatal in just a few minutes. The symptoms are usually multiple, many are non-specific, and some are vague. They can involve many of the body systems. Please be aware that the symptom list below is incomplete and that the symptoms often do not follow this rank ordering at presentation. Moreover, many of the more severe symptoms (eg. below ataxia) are only seen with acute high level CO exposure.

Symptoms in Order of Increasing Severity of CO Poisoning:

--- Headache
--- Dizziness and vertigo on exertion
--- Fatigue, weakness
--- Palpitations
--- Tinnitus
--- Nausea, vomiting
--- Dyspnea on exertion
--- Cutaneous vessel dilation
--- Mental Confusion, difficulty with thinking, speaking
--- Fine manual dexterity abnormal
--- Tachycardia
--- Visual disturbances, blurry vision, double vision
--- Hallucinations, confusion
--- Ataxia
--- Syncope, collapse
--- Tachypnea (increased ventilation), further tachycardia
--- Lactic acidosis
--- Hyperglycemia
--- Hypothermia
--- Cheyne Stokes ventilation
--- Coma, convulsions
--- Pupils fixed, dilated
--- Decerebrate posturing
--- Hypotension severe
--- Cardiac and ventilatory depression
--- Cardiorespiratory failure (death)

Note: This doesn't even tell half of the story regarding symptoms of CO poisoning. There is much more on symptoms in chronic CO poisoning from our own studies in another section of COHQ.