Which symptom is listed as a sign of carbon monoxide poisoning?

• A. Headache
• B. Rash on skin
• C. Nasal congestion
• D. Aching joints

Answer: (A)

Understanding signs of carbon monoxide poisoning: headaches are a classic early clue because carbon monoxide binds to hemoglobin and forms carboxyhemoglobin, which greatly reduces oxygen delivery to the brain. That brain hypoxia commonly produces a headache, and can be accompanied by dizziness or confusion as exposure continues. The other options don’t fit CO poisoning patterns: a rash isn’t caused by CO and suggests a skin or allergic issue; nasal congestion points to infections or allergies; aching joints reflect musculoskeletal problems. In suspected CO exposure, move to fresh air and seek urgent medical care for high‑flow oxygen; severe cases may require hyperbaric oxygen therapy.