Because polycythemia vera (PV) is a rare type of blood cancer, a diagnosis often comes when you see your doctor for other reasons. They will consider your symptoms and refer you to tests for confirmation.

A diagnosis of PV is usually not the result of a physical exam. However, your doctor may observe symptoms of the disease during a routine visit.

Some physical symptoms your doctor may recognize are bleeding gums and a reddish hue to your skin. If you have symptoms or your doctor suspects PV, they will most likely examine and palpate your spleen and liver to determine if they’re enlarged.

In addition, you may need one or more of the following tests for a diagnosis of PV:

A CBC blood test measures the number of red and white blood cells and platelets in your blood. It will also tell your doctor what your hemoglobin level is in your bloodstream.

Hemoglobin is a protein rich in iron that helps red blood cells carry oxygen from the lungs to the rest of the body. And if you have PV, your hemoglobin level will be elevated. Usually, the more red blood cells you have, the higher your hemoglobin level.

A CBC will also measure your hematocrit. Hematocrit is the volume of your blood that’s made up of red blood cells. If you have PV, a higher-than-normal percentage of your blood will be made of red blood cells.

In adults, the following levels can indicate PV:

females assigned at birth (FAABs) males assigned at birth (MAABs)
Hemoglobin16.0 grams per deciliter (g/dL) 16.5 g/dL

However, hemoglobin and hematocrit levels can be misleading when it comes to polycythemia vera.

It’s possible for your CBC to show a normal hematocrit result because of expansion in your blood plasma volume or a normal hemoglobin result if you are also deficient in iron. Sometimes, the CBC may show high white cell and platelet counts, but not always.

For this reason, a higher-than-normal red blood cell count can be a more reliable indicator for PV, though your doctor will need to rule out other causes.

A blood smear looks at your blood sample under a microscope. This can show the size, shape, and condition of your blood cells.

It can detect abnormal red and white blood cells, along with platelets, that can be linked to myelofibrosis and other bone marrow problems. Myelofibrosis is serious bone marrow scarring that can develop as a complication of PV.

Using a blood sample, an erythropoietin test measures the amount of the hormone erythropoietin (EPO) in your blood. EPO is made by the cells in your kidneys and signals stem cells in the bone marrow to make more red blood cells.

If you have PV, your EPO level should be low. This is because your EPO isn’t driving blood cell production. Instead, a JAK2 gene mutation is driving blood cell production.

In adults, values lower than 2.6-18.5 milli-international units per milliliter (mUI/mL) can suggest to your doctor that PV may be at play.

That said, it’s more common to see lower EPO in cases where there is a different underlying cause of polycythemia than cancer.

Bone marrow tests can determine if your bone marrow is making normal amounts of blood cells. If you have PV, your bone marrow is making too many red blood cells, and the signal to make them doesn’t turn off.

There are two main types of bone marrow tests:

During a bone marrow aspiration, a small amount of the fluid part of your bone marrow is removed with a needle. For a bone marrow biopsy, a small amount of the solid part of your bone marrow is removed instead.

These bone marrow samples are sent to a lab for analysis by either a hematologist or a pathologist. These specialists will analyze the biopsies and send your doctor the results within a few days.

The discovery of the JAK2 gene and its mutation in 2005 has also led to improved understanding and diagnosis of PV.

JAK stands for Janus Kinase. This genetic abnormality is found in 98% of PV patients. Having it can cause a disruption in the JAK pathway signaling, resulting in excessive production of blood cells in the body

Both blood and bone marrow samples can be tested for the mutation, making diagnosis easier for doctors.

If your symptoms or other test results suggest polycythemia vera, your doctor may refer you to this test for confirmation.

How can you tell if a person has polycythemia vera?

Only a doctor can diagnose PV based on blood tests, a blood smear, or testing of your bone marrow. In addition, they will look at your physical symptoms. These may include fatigue, itching, and difficulty breathing while lying down, among others.

As more red blood cells accumulate in your blood, more severe symptoms may arise, such as heavy bleeding from small cuts, joint swelling, or bone pain.

Is polycythemia vera cancer?

Polycythemia vera is a form of blood cancer that causes the bone marrow to make too many red blood cells, which slows down blood flow.

What is the life expectancy for polycythemia vera?

With treatment, you can expect to live for at least 14 years after diagnosis. Generally, younger people tend to have a better outlook, but other factors can also impact life expectancy.

Although PV is rare, getting a blood test is one of the best ways to get an early diagnosis and treatment. If your doctor determines that you do have PV, there are ways of managing the disease.

Your doctor will make recommendations based on your age, the progression of the disease, and your overall health.