The evaluation of carbon monoxide poisoning begins with a history and physical examination.

Physical findings in those with carbon monoxide poisoning may include:

• Confusion
• Rapid pulse
• Sweating

The diagnosis of carbon monoxide poisoning must be confirmed through testing.

Tests that may be used to evaluate carbon monoxide poisoning include:

• Chest x-ray
• Arterial blood gas
• Pulse oximetry
• Carboxyhemoglobin level

CO Level	Symptoms
Under 10 percent	no symptoms
20 percent	headache, nausea, vomiting, loss of dexterity
30 percent	confusion, lethargy, EKG changes & ST segment depression
40 to 60 percent	coma
Over 60 percent	death