People with methemoglobinemia don't have blue blood, but people with methemoglobinemia often have bluish or grayish colored skin also known as cyanosis.
Although the persons blood with methemoglobinemia often appears chocolate brown color, because the abnormal hemoglobin cannot carry oxygen effective and makes it look darker than normal red blood.
Instead of bright red, the blood when you have methemoglobinemia, looks chocolate brown and does not turn bright red when exposed to oxygen.
The cause is a problem with hemoglobin, which is the oxygen carrying protein in red blood cells that make it unable to release the oxygen to tissues, which lead to symptoms of low oxygen, also known as hypoxia.
Human blood is always red, although methemoglobinemia causes a specific type of cyanosis where your skin takes on a blue or grayish hue while the blood itself turns a dark, chocolatey brown because the iron in hemoglobin is oxidized and cannot bind oxygen well.
The first signs of methemoglobinemia are bluish skin also known as cyanosis, especially around the lips and nails, and the bluish skin with methemoglobinemia is often also accompanied with other symptoms like shortness of breath, fatigue, dizziness and headache.
The key indicator of methemoglobinemia is also hypoxia, which is low blood oxygen, that does not improve with oxygen.
Sometimes a person with methemoglobinemia may also have noticeably chocolate brown colored blood.
The symptoms of methemoglobinemia will also depend on the severity of the , but methemoglobinemia often starts with mild signs like paleness (10-20% MetHb)and progress to confusion, rapid heart rate and weakness (20-45% MetHb as levels rise.
The early signs of methemoglobinemia, which occur at MetHb of 10-20% are bluish tint to skin, lips and nail beds and is sometimes described as slate gray.
Pale skin or pallor and sometimes no symptoms in early methemoglobinemia in healthy people, but people with underlying issues may feel weakness or fatigue.
Moderate signs of methemoglobinemia at MetHb 2-45% are shortness of breath or dyspnea, headache and dizziness, fatigue and weakness, increased heart rate also known as tachycardia and Rapid breathing also known as tachypnea and nausea and vomiting.
The key diagnostic clues of methemoglobinemia are refractory cyanosis, with bluish skin color that does not go away with supplemental oxygen, chocolate brown colored blood.
And a pulse oximeter that shows low oxygen or SpO2 Gap, but arterial blood gas is (SaO2) is also low and inconsistent.
You should seek emergency care if you have symptoms like seizures, confusion, severe drowsiness, loss of consciousness or extreme difficulty breathing, as severe cases of methemoglobinemia with MetH>50% can be life threatening.
Methemoglobinemia is a blood disorder where too much methemoglobin forms, reducing the blood's ability to carry oxygen to the body, leading to symptoms like bluish skin (cyanosis), headache, dizziness, and shortness of breath, often triggered by certain drugs (like benzocaine, dapsone) or toxins (nitrates in water) and sometimes inherited, with treatment typically involving methylene blue and oxygen.