Why is a carbon monoxide (CO) test done?
This test may be done if you have been exposed to carbon monoxide or if you have unexplained symptoms, such as:
- Headache or dizziness.
- Nausea or vomiting.
- Extreme sleepiness.
- Shortness of breath.
- Confusion or trouble thinking.
How is a carbon monoxide (CO) test done?
A health professional uses a needle to take a blood sample, usually from the arm.
How do you prepare for a carbon monoxide (CO) test?
In general, there's nothing you have to do before this test, unless your doctor tells you to.
What do the results of a carbon monoxide (CO) test mean?
The results are reported as a percentage. They show the amount of carbon monoxide bound to hemoglobin divided by the total amount of hemoglobin (multiplied by 100). This is called the carboxyhemoglobin level.
Results are usually available right away.
Normal
Each lab has a different range for what's normal. Your lab report should show the range that your lab uses for each test. The normal range is just a guide. Your doctor will also look at your results based on your age, health, and other factors. A value that isn't in the normal range may still be normal for you.
High values
High blood carbon monoxide values are caused by carbon monoxide poisoning. Symptoms of carbon monoxide poisoning become more severe as the carbon monoxide levels increase.
Women and children usually have fewer red blood cells than men do. So women and children may have more severe symptoms at lower levels.
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