How Is Pernicious Anemia Diagnosed?
Pernicious anemia is diagnosed using a persons
medical history, physical exam, and tests that can determine the type and cause
of anemia. A doctor can use these methods to find out how severe the problem
is, its cause, and the appropriate treatment. Mild to moderate anemia may have
no signs or symptoms. In fact, anemia is often discovered unexpectedly on
screening tests.
Specialists Involved
Primary care doctors, such as a family doctor, often
diagnose and treat pernicious anemia. Other kinds of doctors may also be
involved, including:
- A neurologist (nervous system specialist)
- A cardiologist (heart specialist)
- A hematologist (blood disease specialist)
- A gastroenterologist (digestive tract disease
specialist)
Medical and Family History
Your doctor may ask detailed questions about many
symptoms, including feeling tired and weak and others listed in the section
What Are the Signs and Symptoms of Pernicious
Anemia? The doctor may ask about any personal or family history of
anemia,
diabetes, or diseases of the immune system. You may be asked
about any surgery you have had, especially stomach surgery. The doctor may also
ask you about your diet and about the medicines you are taking.
Physical Exam
A physical exam may include:
- Checking for pale or yellowish skin and a red,
smooth tongue
- Listening to the heart to check for a rapid
heartbeat or
murmur
- Feeling the abdomen to check the size of the
liver
Your doctor will also order a number of tests or
procedures to be sure about the type of anemia you have and how severe it
is.
Diagnostic Tests and Procedures
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. 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.
Low hematocrit is another sign of anemia.
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 cells that are involved in blood clotting.
- Red blood cell size. The mean cell volume is the
name of a test that measures the average size (volume) of red blood cells. In
pernicious anemia, the red blood cells are usually larger than normal. This is
called macrocytosis (MAK-ro-si-TO-sis).
Tests To Check the Vitamin B12 Level
- Vitamin B12. The level of vitamin B12 in the
bloodstream may be normal or borderline even when the total amount of B12 in
the body is low.
- Folic acid (folate). This is another B vitamin
that can be low when the B12 level is low. A lack of folic acid can also cause
anemia.
- Homocysteine. Homocysteine is high in anemia due
to the lack of vitamin B12 or folic acid. Folate deficiency is more common
because this vitamin is used up more quickly and the dietary need is greater.
In this case, the bloods B12 level can be normal.
- Methylmalonic (METH-il-ma-LON-ik) acid. The level
of methylmalonic acid is high in anemia due to a lack of vitamin B12 or folic
acid. Methylmalonic acid can also be checked with a urine test.
Other Blood Tests
Other blood tests check for:
- The presence of intrinsic factor antibodies and
parietal cell antibodies. These antibodies in the blood may mean that they are
destroying the intrinsic factor or parietal cells.
- Levels of bilirubin, potassium, or cholesterol in
the blood.
- Serum iron and iron binding capacity.
- The number of reticulocytes (re-TIK-u-lo-sites).
Reticulocytes are young, red blood cells. The reticulocyte test is used to see
if the bone marrow is producing red blood cells at the proper rate. A lower
than average number of reticulocytes can mean that the bone marrow is not
making enough red blood cells. The reticulocyte number is low in people with
pernicious anemia.
Schilling Test
The Schilling test is a urine test that measures how
well the body absorbs vitamin B12. It is not used as much now as it was in the
past.
Bone Marrow Tests
In some cases, a doctor may want to do a bone marrow
biopsy or aspiration. A bone marrow biopsy is a minor surgical procedure to
remove a small amount of bone marrow tissue. In a bone marrow aspiration, the
doctor removes a small amount of bone marrow fluid through a needle. Bone
marrow biopsy or aspiration tests whether the bone marrow is healthy and can
show whether the bone marrow is making enough blood cells. |