methemoglobinemia
Meaning of methemoglobinemia: Methemoglobinemia occurs when methemoglobin, a form of hemoglobin unable to carry oxygen, builds up in the blood beyond its normal small proportion.
Definition of methemoglobinemia
Methemoglobinemia is a condition in which methemoglobin, a chemically altered form of hemoglobin that cannot carry oxygen, accumulates in the blood beyond its normal small amount. Because methemoglobin cannot deliver oxygen to tissue the way normal hemoglobin does, tissues throughout the body can receive less oxygen than they need.
Symptoms depend on how much methemoglobin is present and can include headache, dizziness, fatigue, shortness of breath, nausea, rapid heartbeat, loss of muscle coordination, and a bluish discoloration of the skin and lips, reflecting reduced oxygen delivery.
Methemoglobinemia can be acquired, triggered by exposure to certain medications, chemicals, or foods that push hemoglobin toward its methemoglobin form faster than the body can convert it back, or it can be inherited, resulting from a genetic difference that impairs the body's normal ability to keep methemoglobin levels low.
Used in a sentence
The patient's bluish skin discoloration and low oxygen saturation prompted testing that confirmed methemoglobinemia.
Good to know
The bluish skin discoloration seen in methemoglobinemia can resemble the cyanosis of low blood oxygen from a lung or heart problem, though methemoglobinemia arises from an altered blood protein rather than a failure of oxygen intake.
Word origin
Where “methemoglobinemia” comes from
Formed from methemoglobin, from Greek meta- (change) and haima (blood) combined with Latin globus (ball), and the suffix -emia, from Greek haima, meaning a condition of the blood.