symptoms according to percentage carboxyhaemoglobin

Last reviewed 01/2018

There is a characteristic trend of symptoms according to the percentage of carboxyhaemoglobin in the blood:

  • 0-15% carboxyhaemoglobin: typically no symptoms
  • 15-20%:
    • headache
    • confusion
  • 20-40%:
    • nausea
    • fatigue
    • disorientation
    • irritability
  • 40-60%:
    • hallucinations
    • ataxia
    • syncope
    • convulsions
    • coma
  • > 60%: death