Carbon Monoxide, Blood



Quest Diagnostics Test Code: 309

Carbon monoxide is the most common of the gaseous poisons. Malfunctioning or poorly ventilated heating appliances and internal combustion engines are frequent causes of carbon monoxide poisoning. Carbon monoxide combines reversibly with hemoglobin in a manner almost identical to oxygen resulting in a decrease in the amount of oxygen carried by hemoglobin.

Carbon monoxide (CO) is a colorless, odorless gas which is toxic to cells in the body. Carbon monoxide comes from car exhausts, gas-burning devices and cigarette smoking. This substance irreversibly binds to haemoglobin in order to produce a product called carboxyhemoglobin. This prevents oxygen from binding to hemoglobin, and eventually starve the brain and other tissues from oxygen which can eventually be fatal. This test measures the amount of carbon monoxide in the blood. This test is typically performed on someone who exhibits symptoms of carbon monoxide poisoning.

This test is performed in following conditions such as:

• Headache
• Dizziness
• Blurred vision
• Nausea
• Weakness
• Confusion
• Sleepiness

Also Known As: Carboxyhemoglobin


People testing due to industrial exposure should have their sample collected in the late afternoon as close to their end of shift as possible due to the short amount of time it takes for CO to be eliminated from the body.


Specimen Collected
  • Blood
Estimated Time Taken

Turnaround for this test is typically 3-4 business days.