Carbon monoxide poisoning

Carbon monoxide (CO) poisoning is diagnosed in 1 in 100,000 people per year in the UK, more commonly in winter and in more deprived areas. Toxicity occurs mainly through the formation of carboxyhaemoglobin (COHb), causing ischaemia of vital organs. Features are non-specific and include headache, gastrointestinal upset, dizziness, weakness, convulsions, coma, chest pain and dyspnoea. Neuropsychiatric features can appear up to 40 days after the initial exposure. The diagnosis can be missed unless a history of exposure to sources of CO is elicited or a CO alarm triggered.