Which of the following lists are common symptoms of carbon monoxide poisoning?

• A. Nausea, vomiting, headache, weakness, and unconsciousness.
• B. Chest pain and shortness of breath only.
• C. Fever and chills.
• D. Dizziness and blurred vision only.

Answer: (A)

Carbon monoxide poisoning causes tissue hypoxia because carbon monoxide binds strongly to hemoglobin, forming carboxyhemoglobin and preventing oxygen from being delivered to tissues. The most common presentation reflects both brain and gastrointestinal involvement: nausea, vomiting, headache, weakness, and, in more severe cases, unconsciousness. This combination is widely recognized as the typical pattern of exposure, especially in enclosed spaces with faulty heating or exhaust sources, and it can easily be mistaken for a flu-like illness because there’s no fever or obvious source.

The other lists don’t capture this broad, characteristic picture. Chest pain and shortness of breath can occur, particularly in people with heart disease, but they don’t include the concurrent GI and neurologic symptoms that often accompany CO exposure. Fever and chills are not typical of CO poisoning, and dizziness or blurred vision may occur but are not by themselves the most representative or comprehensive sign set.