 The main manifestations of carbon monoxide poisoning develop in the organ systems most dependent on oxygen use , the central nervous system and the heart . The initial symptoms of acute carbon monoxide poisoning include headache , nausea , malaise , and fatigue . These symptoms are often mistaken for a virus such as influenza or other illnesses such as food poisoning or gastroenteritis . Headache is the most common symptom of acute carbon monoxide poisoning ; it is often described as dull , frontal , and continuous . Increasing exposure produces cardiac abnormalities including fast heart rate , low blood pressure , and cardiac arrhythmia ; central nervous system symptoms include delirium , hallucinations , dizziness , unsteady gait , confusion , seizures , central nervous system depression , unconsciousness , respiratory arrest , and death . Less common symptoms of acute carbon monoxide poisoning include myocardial ischemia , atrial fibrillation , pneumonia , pulmonary edema , high blood sugar , lactic acidosis , muscle necrosis , acute kidney failure , skin lesions , and visual and auditory problems . 
