What are the symptoms of carbon monoxide poisoning?

• A. Coughing, sneezing, sore throat, and runny nose.
• B. Rash, itching, hives, and swelling.
• C. Nausea, vomiting, headache, weakness, and unconsciousness.
• D. Abdominal pain, diarrhea, and fever.

Answer: (C)

Carbon monoxide poisoning produces tissue hypoxia because CO binds to hemoglobin more readily than oxygen, so delivery of oxygen to tissues is impaired. The effects are nonspecific and tend to evolve with exposure, starting with headache, dizziness, and weakness, often accompanied by nausea and vomiting, and can progress to unconsciousness as exposure increases. The symptoms described—nausea, vomiting, headache, weakness, and unconsciousness—align with this progression and are characteristic of CO poisoning. Other symptom groups, like coughing with runny nose or sore throat, rash or hives with swelling, or abdominal pain with fever, point to other conditions such as viral infections, allergic reactions, or gastroenteritis, not CO poisoning. If CO exposure is suspected, get to fresh air and seek emergency care immediately.