一氧化碳中毒是吸入过量一氧化碳所导致的一种似中毒的缺氧现象。

由于一氧化碳与体内血红蛋白的亲和力比氧与血红蛋白的亲和力大200－300倍，而碳氧血红蛋白较氧合血红蛋白的解离速度慢3600倍，当一氧化碳浓度在空气中达到35ppm，就会对人体产生损害，导致身体出现缺氧的情况，可以致命。而由于碳氧血红蛋白呈樱桃红色，因此因一氧化碳中毒而死的人士的皮肤会呈现这种颜色。

一氧化碳中毒后，先是严重头痛，接着是恶心、呕吐和呼吸急促，之后中毒者会精神错乱、肌肉无力，一用力就会觉得头晕。因此中毒者经常无法移动很远，也就无法逃出中毒环境。最后丧失意识和昏迷。结果导致死亡，死因可能是心律不齐，以及心脏和脑受损。

Carbon monoxide poisoning occurs after too much inhalation of carbon monoxide (CO). Carbon monoxide is a toxic (poisonous) gas, but, being colorless, odorless, tasteless, and initially non-irritating, it is very difficult for people to detect. Carbon monoxide is a product of incomplete combustion of organic matter due to insufficient oxygen supply to enable complete oxidation to carbon dioxide (CO₂). It is often produced in domestic or industrial settings by motor vehicles that run on gasoline, diesel, methane, or other carbon-based fuels and from tools, gas heaters, and cooking equipment that are powered by carbon-based fuels such as propane, butane and charcoal. Exposure at 100 ppm or greater can be dangerous to human health.