Normal Values:

The following values represent the percentage of hemoglobin derivatives based on total hemoglobin:

• Carboxyhemoglobin: 3% (but may be as high as 15% in smokers)
• Methemoglobin: less than 3%
• Sulfhemoglobin: undetectable

What abnormal results mean:

High levels of hemoglobin derivatives can lead to significant health problems. The altered forms of hemoglobin do not allow oxygen to be moved properly through the body. This can lead to tissue death.

The following values, except sulfhemoglobin, represent the percentage of hemoglobin derivatives based on total hemoglobin:

Carboxyhemoglobin:

• 20% symptoms of carbon monoxide poisoning begin to appear
• 30% severe carbon monoxide poisoning present
• 50-80% results in deadly carbon monoxide poisoning

Methemoglobin:

• 10-25% results in cyanosis
• 35-40% results in shortness of breath and headache
• Over 60% results in lethargy and stupor
• Over 70% results in death

Sulfhemoglobin:

• Values of 10 grams per deciliter (gm/dL) cause bluish skin color due to lack of oxygen (cyanosis), but do not cause harmful effects