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What is it?

Carboxyhemoglobin (car-BOXY-heem-uh-glo-bun) is a laboratory test to see if you have been exposed to carbon monoxide (CO). Carbon monoxide is a poisonous gas that you cannot see or smell. Hemoglobin is one of the main contents of red blood cells (RBC) that carries oxygen throughout your body. Carbon monoxide replaces the oxygen in your RBCs, forming carboxyhemoglobin. Carboxyhemoglobin cannot carry oxygen. Following are some sources of carbon monoxide:

  • A gas furnace or stove that is not working well.
  • Running the motor of your car inside a closed garage.
  • Burning charcoal indoors.
  • Inhaling smoke from a fire.
  • Smoking tobacco.

Why do I need it?

Your caregiver may want you to have this test if you have been exposed to CO. You may need this test if these symptoms have started for no reason that you know of:

  • Headache.
  • Nausea (feeling sick to your stomach) or vomiting (throwing up).
  • Irritability (getting angry easily).
  • Dizziness.

How do I get ready for the test?

Your caregiver will tell you when to have your blood test done. The blood test should be done as soon as possible after exposure to CO. It may be done before or after eating.

How is the specimen collected?

A caregiver will put a wide rubber strap around your arm and tighten it. Your skin will be cleaned with alcohol. A small needle attached to a special test tube will be put into a vein in your arm or hand. The tube has suction to pull the blood into it. When the tube is full, the rubber strap, needle and tube are removed. The caregiver will press a piece of cotton where the needle was removed. You may be asked to hold the cotton on the site for a few minutes to help stop the bleeding. Tape may then be put over the cotton on your arm.

What do I do after the test?

You may remove the tape and cotton in about 20 to 30 minutes. Call your caregiver to get the results of your test. Your caregiver will explain what your test results mean for you. Follow the instructions of your caregiver.

Care Agreement

You have the right to help plan your care. To help with this plan, you must learn about your lab tests. You can then discuss the results with your caregivers. Work with them to decide what care may be used to treat you. You always have the right to refuse treatment.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.