Which of the following is a common symptom of carbon monoxide poisoning?

• A. Headache
• B. Fever
• C. Rash
• D. Cough

Answer: (A)

Headache is a common sign of carbon monoxide poisoning because CO binds to hemoglobin with much higher affinity than oxygen, forming carboxyhemoglobin and preventing oxygen from reaching the brain and other tissues. That lack of oxygen often triggers headaches and can also cause dizziness, weakness, nausea, and confusion. Fever, rash, and cough aren’t typical primary symptoms of CO poisoning; fever and rash suggest infection or allergy, and a cough points to respiratory illnesses or irritants. Since carbon monoxide is colorless and odorless, detectors and immediate fresh air are crucial—if exposure is suspected, move to fresh air and seek medical help right away.