What are the symptoms of carbon monoxide poisoning?

Unfortunately, the symptoms that are a result of carboxyhemoglobin saturation are easily overlooked because they are often flu-like. With mild exposure, people report that they experience headaches, fatigue and nausea. Medium exposure can cause a severe throbbing headache, drowsiness, disorientation, confusion and an accelerated heart rate. Extreme exposure could even cause unconsciousness, convulsions, cardiorespiratory failure, coma and possibly death.