The most common symptoms of CO poisoning can be confused with “flu-like” symptoms — such as headache, dizziness, weakness, upset stomach and vomiting. It can also cause sleepiness, blurred vision, ringing in the ears, breathing problems, and confusion. Because CO poisoning is more common in the colder months when colds and flu are common, you might mistake CO poisoning for a cold or flu.
If you breathe in a lot of CO, it can make you pass out or kill you. People who are sleeping or under the influence of drugs or alcohol can die from CO poisoning before they have symptoms.
Breathing low levels of CO over a few hours can be just as harmful as breathing high levels for a few minutes. If symptoms go away when you leave your home, but come back when you return, there may be a CO problem in your home. Pets will also suffer these symptoms and can serve as a warning.
Go outside immediately to get fresh air, then dial 9-1-1 if: