How Is Polycythemia Vera Diagnosed?
Polycythemia vera (PV) may not cause signs or
symptoms for years. Thus, the disease often is found during routine
blood
tests done for other reasons. If the results of your blood tests aren't
normal, your doctor may want to do more tests.
Your doctor will diagnose PV based on your signs and
symptoms, your age and overall health, your medical history, a physical exam,
and the results from tests.
During the physical exam, your doctor will look for
signs of PV. He or she will check for an enlarged spleen, red skin on your
face, and bleeding from your gums.
If your doctor confirms that you have polycythemia,
the next step is to find out whether you have primary polycythemia
(polycythemia vera) or secondary polycythemia.
Your medical history and physical exam may confirm
which type of polycythemia you have. If not, you may have tests that check the
level of the hormone erythropoietin (EPO) in your blood.
People who have PV have very low levels of EPO.
People who have secondary polycythemia usually have normal or high levels of
EPO.
Specialists Involved
If your primary care doctor thinks you have PV, he
or she may refer you to a hematologist. This is a doctor who specializes in
diagnosing and treating blood diseases and conditions.
Diagnostic Tests
You may have a number of different blood tests to
diagnose PV. These tests include a
complete
blood count (CBC) and other tests, if necessary.
Complete Blood Count
Often, the first test used to diagnose PV is a CBC.
The CBC measures many different parts of your blood.
This test checks your hemoglobin (HEE-muh-glow-bin)
and hematocrit (hee-MAT-oh-crit) levels. Hemoglobin is the iron-rich protein in
red blood cells that carries oxygen to the body. Hematocrit is a measure of how
much space red blood cells take up in your blood. A high level of hemoglobin or
hematocrit may be a sign of PV.
The CBC also checks the number of red blood cells,
white blood cells, and platelets in your blood. Abnormal results may be a sign
of PV, a blood disorder, an infection, or another condition.
Other Blood Tests
Blood smear. For this test, a small
sample of blood is drawn from a vein, usually in your arm. The sample of blood
is put on a glass slide. A microscope is then used to look at your red blood
cells.
A blood smear can show whether you have a
higher-than-normal number of red blood cells. The test also can show abnormal
types of blood cells that are linked to myelofibrosis and other conditions
related to PV.
Erythropoietin level. This blood
test measures the level of EPO in your blood. EPO is a hormone that stimulates
bone marrow to make new blood cells. People who have PV have very low levels of
EPO. People who have secondary polycythemia usually have normal or high levels
of EPO.
Bone Marrow Tests
Bone
marrow tests are used to check whether your bone marrow is healthy. These
tests also show whether your bone marrow is making normal amounts of blood
cells.
If the tests show that your bone marrow is making
too many blood cells, it may be a sign that you have PV. |