How Is Aplastic Anemia Diagnosed?
Aplastic anemia is diagnosed using a medical and
family history, a physical exam, and tests to discover the type and cause of
anemia. Your doctor can use these methods to find out how severe the anemia is
and to decide the appropriate treatment.
Specialists Involved
A person with suspected aplastic anemia may be
referred to a hematologist (an expert in treating blood conditions).
Medical and Family History
During a medical history, your doctor may ask
detailed questions about many kinds of symptoms. He or she may ask if you have
ever had problems with
anemia,
had an illness or condition that could cause anemia, or been exposed to drugs,
chemicals, or radiation. The doctor will ask about medicines you are taking to
see if they might be a cause of the anemia. The doctor will also ask if your
family members have ever had any kind of anemia.
Physical Exam
Your doctor will do a physical exam to see how
severe the anemia is and to check for its possible causes. This exam may
include:
- Checking for pale or yellowish skin
- Listening to the heart for rapid or irregular
heartbeats
- Listening to the lungs for rapid or uneven
breathing
- Feeling the abdomen to check the size of the
liver and spleen and checking for swelling in the legs
- Checking for signs of bleeding
Diagnostic Tests and Procedures
Several tests of the blood and bone marrow may be
used to diagnose aplastic anemia. The reasons for testing are to:
- Confirm a diagnosis of aplastic anemia and look
for its cause
- Rule out blood cancers that can cause bone marrow
failure
- Determine the severity of the aplastic
anemia
- Check for the presence of paroxysmal nocturnal
hemoglobinuria
Complete Blood Count
Usually, the first test used to diagnose anemia is a
complete blood count (CBC). The CBC tells a number of things about a
persons blood, including:
- The hemoglobin level. Hemoglobin is the iron-rich
protein in red blood cells that carries oxygen through the body. The normal
range of hemoglobin levels for the general population is 1115 g/dL. A low
hemoglobin level means a person has anemia.
- The hematocrit (hee-MAT-oh-crit) level. The
hematocrit level measures how much of the blood is made up of red blood cells.
The normal range for hematocrit levels for the general population is 3243
percent. A low hematocrit level is another sign of anemia.
The normal range of these levels may be lower in
certain racial and ethnic populations. Your doctor can explain your individual
test results.
The CBC also checks:
- The number of red blood cells. Too few red blood
cells means a person has anemia. A low number of red blood cells is usually
seen with either a low hemoglobin or a low hematocrit level, or both.
- The number of white blood cells. White blood
cells are involved in fighting infection.
- The number of platelets in the blood. Platelets
are small cell fragments that are involved in blood clotting.
- Red blood cell size. The mean cell volume
measures the average size (volume) of red blood cells.
Reticulocyte Count
This test measures the number of new red blood cells
in the blood. It helps doctors find out whether bone marrow is producing red
blood cells at the proper rate. A lower than average level can mean that the
bone marrow is not making enough red blood cells. The reticulocyte
(re-TIK-u-lo-site) level is low in people with aplastic anemia.
Bone Marrow Tests
This test looks at the bone marrow to see if it is
healthy and if it is making enough blood cells. A small amount of bone marrow
may be removed and examined. Removing a small bit of liquid bone marrow is
called aspiration. Removing bone marrow tissue is called biopsy.
A bone marrow aspiration may be done to find what is
causing the low production of blood cells. Since blood cells are formed inside
the bones, doctors use a needle to remove a small amount of liquid bone marrow.
The sample is then examined under a microscope to check for abnormal cells.
A bone marrow biopsy is usually done at the same
time, especially if an aspiration was not productive. A small number of bone
marrow cells with a small piece of bone is removed using a needle. This test
checks the number and type of cells in the bone marrow. In aplastic anemia, the
bone marrow has a lower than normal number of cells.
Other Tests
Additional tests may be used to help diagnose
aplastic anemia, including:
- X ray,
CT scan, or
ultrasound of the abdomen to look for an enlarged spleen or
lymph nodes, which could indicate blood cancer. These tests also may be used to
examine the kidneys, arms, and hands, which are sometimes abnormal in young
people with Fanconi anemia.
- Chest x ray to provide a picture of the heart and lungs and
rule out infection.
- Liver tests and viral studies to check for
hepatitis and viruses.
- Tests that check vitamin B12 and folate levels to
rule out anemia due to vitamin deficiency.
- Blood tests for paroxysmal nocturnal
hemoglobinuria and to check the immune system for antibodies.
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