Are your red blood cells enlarged? (Macrocytosis) - Let's find out about this!

Have you ever looked at a blood test report and noticed that your red blood cells are larger than normal (enlarged red blood cells)? Or has your doctor ever told you about a condition called “Macrocytosis”? This may sound a little scary, but don’t worry. Macrocytosis is not a disease, it’s just a change in the red blood cells.

What is Macrocytosis?

Simply put, Macrocytosis means that your red blood cells are larger than normal. This is not considered a disease, but it can be a sign of something wrong with our body. This is only known when you have a complete blood count (CBC)/ Full Blood Count ( FBC ). Most often, doctors do this `CBC` test to see how our body's cells are functioning and how healthy they are.

The `CBC` report has a value called `MCV (Mean Corpuscular Volume)`. This is a measure of the average size of your red blood cells. If an adult`s `MCV` value is more than 100 femtoliters (`100 fL`), we call that condition Macrocytosis.

Most of the time, this is not a serious problem. However, sometimes these enlarged red blood cells may not receive the nutrients they need. Then, those cells cannot do their main job, which is to carry oxygen throughout the body. This condition is called `Macrocytic Anemia` . If `Macrocytic Anemia` is not treated properly, it can lead to serious health problems.

How common is this condition?

Roughly speaking, between 2% and 4% of the world's population has Macrocytosis. The majority of these people, about 60%, have Macrocytosis along with anemia.

However, macrocytosis without anemia is more common among young children and the elderly.

What are the symptoms of Macrocytosis?

Most of the time, the only sign of macrocytosis is an elevated MCV on the CBC report. This simply means that your red blood cells are larger. If symptoms occur, they are related to the underlying cause of the enlarged red blood cells.

For example, if you have `Macrocytic Anemia`, you may experience symptoms such as weakness , fatigue, and pale skin , which are common symptoms of anemia. Also, if the cause is a nutritional deficiency, you may experience symptoms such as diarrhea, memory loss, and loss of balance .

That means, since there are many causes of macrocytosis, the symptoms can also vary.

What are the causes of macrocytosis?

Blood cells are produced in our bone marrow. So, problems in the production of red blood cells in this bone marrow and problems in the structure of red blood cells can cause Macrocytosis. Sometimes, if you have too many immature red blood cells, called `reticulocytes`, in your blood, then the `MCV` value can also increase. This is because these `reticulocytes` are larger in size than mature red blood cells.

Some of the main causes of macrocytosis are:

Nutritional deficiencies

Nutrients like vitamin B12 and folate (vitamin B9) are essential for our bodies to make healthy red blood cells. If you don't get enough of these nutrients from the food you eat, or if your body can't absorb them due to some disease, your red blood cells won't grow properly. A deficiency of vitamin B12 and folate can cause a condition called `Macrocytic Anemia`. For example, some people don't eat enough green vegetables and fruits. This can lead to folate deficiency. Also, people who are completely vegan can develop a vitamin B12 deficiency.

Some medications

Macrocytosis can also be caused by various medications. The most common of these include hydroxyurea, a medicine used to treat sickle cell disease, various chemotherapy drugs used to treat cancer, and antiretroviral therapy (ART) used to treat HIV infection. If you are taking any of these medications, your doctor will likely be aware of them.

Alcohol use

Excessive alcohol consumption is also a major cause of Macrocytosis. Alcohol reduces the body's ability to absorb nutrients, especially those needed to make healthy red blood cells.

Liver disease

Macrocytosis can also be a sign of liver disease. Liver disease is often, but not always, associated with alcohol use. However, liver disease can also occur for other reasons.

Hemolytic anemia

In a condition called ``Hemolytic anemia,'' your red blood cells die prematurely due to an underlying condition. When this happens, your body releases ``reticulocytes,'' (immature red blood cells) into the bloodstream to make up for the shortage. These immature red blood cells are not as capable of carrying oxygen as mature red blood cells.

Excessive bleeding

If you lose a large amount of blood, whether from an accident, surgery, or other cause, your body will add reticulocytes to your blood to make up for the loss. As in hemolytic anemia, immature cells enter the blood prematurely.

Myelodysplastic syndrome

This is a type of cancer that develops in the bone marrow. This condition prevents the bone marrow from producing healthy red blood cells.

Hypothyroidism

Macrocytosis can also occur in people with hypothyroidism, an underactive thyroid gland. It can occur with or without anemia.

Sometimes, no clear cause can be found for macrocytosis, especially if you only have macrocytosis without anemia.

How do you know if you have macrocytosis?

As we mentioned earlier, macrocytosis is a term that describes enlarged red blood cells, not an official disease. If the MCV value on your CBC report is greater than 100 fL, it means that your red blood cells are larger than normal.

Sometimes doctors can guess the cause of Macrocytosis based on the severity of the condition. For example, if the MCV is very high (around 110 – 115 fL), it could be a sign of a more severe macrocytic anemia, such as megaloblastic anemia.

Tests to find the cause of macrocytosis

If your doctor is concerned about your enlarged red blood cells, he or she will ask you questions to find out the cause. He or she may ask about your medical history, medications you take, your diet, and alcohol use . In addition, he or she may also do some other tests:

• Peripheral blood smear:This involves taking a sample of your blood and looking at it under a microscope to see if there are any abnormalities that could be causing Macrocytosis, such as problems with red blood cell growth.
• Vitamin B12 and folate level test: If the blood levels of vitamin B12 or folate are low, it means that there is a nutritional deficiency that is not getting the nutrients needed to form red blood cells properly.
• Reticulocyte count: This test measures the number of immature red blood cells in your blood sample. This can help determine if this is the cause of your high MCV.
• Liver function test: This tests how well your liver is working to absorb the nutrients needed to make healthy red blood cells.
• Bone marrow biopsy: This test may be done if your doctor suspects that you have a condition that is interfering with your red blood cell production. This involves taking a small sample of your bone marrow and examining the cells under a microscope to see if there are any abnormalities.

How is Macrocytosis treated?

If you have no symptoms of anemia, and your test results show no other abnormalities, you may not need any treatment. Otherwise, treatment will depend on the cause of your high red blood cell count.

• If your macrocytosis is caused by a nutritional deficiency, you may need to change your diet or take vitamin supplements .
• If the problem is with a medication you are taking, your doctor may be able to change the dosage or prescribe a different medication .
• If you have severe anemia along with macrocytosis, you may need a blood transfusion .

The most important thing is to follow the treatment plan your doctor gives you exactly, regardless of the cause of your macrocytosis.

Can Macrocytosis be cured?

In most cases, macrocytosis will reverse itself when the underlying cause is treated. Ask your doctor how treatment will affect your health.

How to reduce the risk of macrocytosis?

We may not be able to prevent everything that can cause macrocytosis. However, we can reduce our risk by adopting healthy habits. For example:

• Adding foods rich in vitamin B12 and folate – fish, dairy products, eggs , leafy greens, and fortified cereals – to your diet can reduce the risk of developing macrocytic anemia.
• It is very important to limit alcohol consumption .
• Also, don't skip annual blood tests. Macrocytosis is often found incidentally during a routine blood test. Early diagnosis and treatment can prevent the condition from getting worse.

What happens if macrocytosis is left untreated?

Only a doctor can determine whether your Macrocytosis is something to be concerned about. If you have Macrocytosis along with anemia, it is essential to seek treatment. If left untreated, Macrocytic Anemia can lead to serious health problems.

What should I ask the doctor?

If you find out that your red blood cells are larger than normal, follow your doctor's advice on what to do. You may want to ask questions like:

• Should I be worried about my high MCV?
• What tests will I need to find the cause of macrocytosis?
• Will I need to treat the cause of my enlarged red blood cells?
• What lifestyle changes can I make to manage this Macrocytosis condition?

Finally, remember (Take-Home Message)

Macrocytosis or a high MCV is not always a cause for concern. So don't be alarmed if your CBC report shows these values. Get your doctor's guidance on how to interpret your results. Depending on your results, your doctor may suggest dietary changes or vitamin supplements. Don't be afraid to ask how your treatment will affect your blood cells and overall health. Staying healthy is the most important thing!