Methemoglobinemia: Symptoms & Signs

Medically Reviewed on 8/28/2020

Methemoglobinemia is a disorder of the blood that causes increased levels of an atypical form of hemoglobin that is unable to deliver oxygen to the body tissues efficiently.

In people affected by beta-globin type methemoglobinemia, the only symptom is cyanosis, which is a bluish discoloration of the skin, mucous membranes, or the area underneath the fingernails due to a lack of oxygen in the blood. Cyanosis is also a possible symptom of acquired methemoglobinemia. Other associated symptoms can include

Causes of methemoglobinemia

Methemoglobinemia can either be an inherited, congenital disorder or it may be acquired during life. Most cases of methemoglobinemia are acquired rather than inborn. Toxins or the use of certain medications can cause acquired methemoglobinemia.

Other methemoglobinemia symptoms and signs

  • Cyanosis
  • Deterioration of Mental Functioning
  • Fatigue
  • Headache
  • Lethargy
  • Loss of Consciousness
  • Shortness of Breath
  • Stupor


Sickle cell disease is named after a farming tool. See Answer

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Jameson, J. Larry, et al. Harrison's Principles of Internal Medicine, 20th Ed. New York: McGraw-Hill Education, 2018.