What is Macrocytosis?

Macrocytosis which is also known by the name of megaloblastic anemia is a pathological condition of the blood condition in which the size of the red blood cells are abnormally large, and their quantity is also insufficient, causing the blood to carry less oxygen throughout the body. This causes a variety of symptoms as the condition progresses with time. In Macrocytosis, different organs of the body do not get the required oxygen which is essential for their normal functioning.


The symptoms of Macrocytosis range from mild to extremely severe and include fatigue, problems with concentration, dizziness and shortness of breath. In severe cases of Macrocytosis the affected individual will experience neurological symptoms to include confusion, dementia, depression, imbalance, and numbness or tingling in the extremities. If an individual experiences neurological symptoms due to Macrocytosis then it calls for emergent medical attention as the symptoms may become permanent if the condition is not treated early.


Macrocytosis is basically caused due to deficiencies in vitamin B12 and folate which are the two essential nutrients required by the body to make red blood cells. These can arise due to problems with the digestive system due to which these nutrients are not able to be absorbed by the body. Pernicious Anemia which is an inherited medical condition is the primary cause of Macrocytosis as this condition interferes with the absorption of vitamin B12. Diet which does not have vitamin B12 in it is also one of the causes of Macrocytosis. This condition is perfectly treatable and the best way to treat Macrocytosis is by taking supplements for vitamin B12 and folate which are easily available. The treatment will not only treat but also prevent any sort of complications of Macrocytosis.


What is Macrocytosis?

What Causes Macrocytosis?

Macrocytosis may be called as a nutrition deficiency as the main cause of this condition is deficiency in vitamin B12 and folate. Pernicious anemia is a medical condition which interferes with the absorption of vitamin B12. Pernicious anemia is a hereditary condition and an individual is born with this condition. There are also certain other medical conditions which may impair adequate absorption of vitamin B12 and folate from the food that is ingested and these conditions are Crohn's disease and celiac disease. Macrocytosis also tends to be caused by alcohol abuse. Macrocytosis can also be caused by conditions like leukemia, myelodysplasia, and myelofibrosis.

What are the Symptoms of Macrocytosis?

Mild cases of Macrocytosis are relatively asymptomatic. In moderate cases of Macrocytosis, symptoms may include fatigue, weakness, or issues with digestion. There may also be some neurological symptoms experienced like confusion or numbness and tingling in the extremities suggestive of nerve damage due to Macrocytosis. Some of the other symptoms of Macrocytosis are:

  • Bleeding gums
  • Constipation alternating with diarrhea
  • Problems with concentration
  • Pale skin
  • Shortness of breath
  • Tongue swelling.

How is Macrocytosis Treated?

For extremely mild cases of Macrocytosis, there is no treatment required. For moderate cases of Macrocytosis, treatment in the form of vitamin B12 and folate supplementation is recommended. This supplementation can be given orally in the form of medications or by modifying the diet switching to a diet which is richer in vitamin B12 and folate.

If Macrocytosis is caused due to some other medical condition like Crohn Disease or celiac disease then the vitamins will be supplemented by way of injections until the time the underlying condition gets treated. In extreme and rare cases, vitamin supplementation may be required for a relatively long term for individuals with Macrocytosis.

Pramod Kerkar

Written, Edited or Reviewed By:


Pain Assist Inc.

Last Modified On: February 12, 2018

This article does not provide medical advice. See disclaimer


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