Aplastic anemia is when your bone marrow can’t make enough healthy blood cells, including red blood cells, white blood cells, and platelets. A CBC measures blood cell levels and is used to diagnose aplastic anemia.

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Aplastic anemia (AA) is a disorder where your bone marrow can’t make enough healthy blood cells for your body to function properly. It can cause potentially serious complications if left untreated.

A complete blood count (CBC) measures the levels of different types of blood cells in your body. It’s one of the tests that you’ll have if a doctor or healthcare professional suspects that you have AA. Continue reading to find out more about CBC testing for AA.

Learn more about AA.

A CBC is a common blood test. You’ve likely had this test done as a part of a routine physical. Having a CBC allows a doctor to assess the levels of different types of blood cells in your body. These include:

  • Red blood cells (RBCs): RBCs are cells that carry oxygen to your body’s tissues and also carry carbon dioxide away.
  • White blood cells (WBCs): WBCs are immune cells that help to protect your body from infections.
  • Platelets: These are tiny blood cells that help your blood to clot.

A CBC also measures other blood parameters like hemoglobin, hematocrit, and mean corpuscular volume (MCV).

People with AA have pancytopenia, which means that the levels of all three types of their blood cells are lower than normal. This is the result of their bone marrow not making enough healthy blood cells. Pancytopenia can cause:

When are your blood counts too low?

The table below shows the normal ranges for blood cell counts measured in cells per microliter (μL) of blood. Values below the normal ranges are considered to be low.

Men (μL)Women (μL)
RBC count4.7–6.1 million4.2–5.4 million
WBC count5,000–10,0004,500–11,000
Platelet count150,000–400,000150,000–400,000

Normal ranges can also vary slightly by the lab that’s doing the analysis. Because of this, always be sure to check your specific lab report when going over your test results.

The diagnostic criteria for AA involve blood counts. Individuals with AA must have two or more of the following:

  • RBC count less than 40,000 cells/μL
  • WBC count less than 500 cells/μL
  • platelet count less than 20,000 cells/μL

Language Matters

You’ll notice we use the binary terms “women” and “men” in this article. While we realize these terms may not match your gender experience, they are the term used by the researchers whose data was cited. We try to be as specific as possible when reporting on research participants and clinical findings.

Unfortunately, the studies and surveys referenced in this article didn’t report data for or may not have had participants who are transgender, nonbinary, gender nonconforming, genderqueer, agender, or genderless.

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There are also other tests used to diagnose AA. For example, along with a CBC, a doctor will also order a blood smear. This allows them to look at the number, size, and shape of your different blood cells under a microscope.

Another part of the diagnostic criteria for AA is that your bone marrow is hypocellular, meaning that the number of cells in your bone marrow is less than normal. To check for this, a doctor will do a bone marrow aspiration and biopsy.

A doctor may also order other tests for additional causes of low blood counts.

Nutritional deficienciesfolate, B12, iron
Infectionsviral hepatitis, HIV, Epstein-Barr virus, cytomegalovirus (CMV)
Autoimmune conditionsC-reactive protein, erythrocyte sedimentation rate, antinuclear antibody, rheumatoid factor
Lymphoproliferativeflow cytometry or cytogenetics
Medication or toxin exposurecareful review of medical history and any medications

After you’ve received a diagnosis of AA, your treatment will depend on factors like the severity of your AA as well as your age and overall health.

If your symptoms have an identifiable cause, such as a medication or infection, a doctor will work to address this.

For younger individuals in good overall health, a stem cell transplant may be recommended. This has the potential to cure AA for some people.

Other potential treatments include:

There are two different types of AA. You can either develop AA or inherit it.

Developed AA is when something triggers the development of AA. It’s believed that this trigger causes your immune system to attack stem cells in your bone marrow, reducing the amount of healthy blood cells.

Potential triggers may be a medication, infection, or exposure to an environmental toxin. Many times, developed AA has no identifiable cause. This is called idiopathic AA. Most people with AA have idiopathic AA, about 65%.

In rare situations, you can inherit AA. Inherited AA is caused by gene changes that are passed down from one or both of your parents. Examples of inherited conditions that can lead to AA include Fanconi anemia and dyskeratosis congenita.

Does aplastic anemia affect red blood cells or white blood cells?

AA generally affects all three types of blood cells. These are RBCs, WBCs, and platelets.

What is the hemoglobin level for aplastic anemia?

A CBC also measures hemoglobin, the part of the RBC that carries oxygen. A normal hemoglobin level is 14–18 grams per deciliter (g/dL) in men and 12–16 g/dL in women.

Hemoglobin levels in AA are typically low. One older study reported that it can be less than 10 g/dL.

Is MCV high in aplastic anemia?

MCV is also included in a CBC. It measures the average size and volume of your RBCs. The normal range for MCV is 80–100 femtoliters.

AA is considered to be a normocytic anemia, meaning that MCV is in the normal range. In normocytic anemia, you have fewer RBCs, but they’re still a normal size.

AA happens when your bone marrow can’t make enough healthy blood cells. It leads to pancytopenia, which is low levels of RBCs, WBCs, and platelets.

A CBC can measure the levels of your blood cells as well as other blood-related parameters. There are specific diagnostic criteria for AA that include blood counts and the number of cells found in a bone marrow sample.

The treatment for AA can depend on how severe it is as well as your age and overall health. AA can lead to potentially serious complications if it isn’t treated.