Exams and Tests

If you are exposed to carbon monoxide or if carbon monoxide poisoning is suspected, your doctor will ask questions about your medical history. Questions may include how long symptoms have been present, what the source of possible exposure to carbon monoxide is, how many other people (family members or coworkers) have the same symptoms, and what home heating and cooking appliances have been used. With this information, your doctor may decide that a test for carbon monoxide is necessary.

The standard test for carbon monoxide measures the amount of hemoglobin that has bonded with carbon monoxide. This amount is also called the carboxyhemoglobin (COHb) level.

Testing should never delay treatment. Treatment should be started as soon as possible.

Other tests such as an arterial blood gas (ABG) and a complete blood count (CBC) also may be done if you have or are suspected of having carbon monoxide poisoning. These tests may be done to evaluate your overall health or to identify problems caused by carbon monoxide poisoning.

A handheld breath analyzer measures how much carbon monoxide is in the air you exhale. This test measures high levels of the gas but may not be reliable in detecting low levels.

Other tests

Questionnaires and other tests may be used to detect subtle changes in your ability to think clearly, if carbon monoxide poisoning is suspected. They also may be used to determine what other treatment is needed.

If you do have carbon monoxide poisoning, you will probably have tests to check for heart damage, such as ECG and cardiac enzyme studies.

Early Detection

There is no routine screening for carbon monoxide poisoning. If carbon monoxide poisoning is suspected, further tests will be done.

In the winter months, carbon monoxide poisoning may be suspected in people who go to the emergency room with symptoms of a severe headache, nausea, or dizziness. Information about a person's home, workplace, and any illness of family members and coworkers is often gathered to determine whether a test for carbon monoxide should be done.