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What It Is and How It’s Treated
Anemia occurs when there are too few normal, healthy red blood cells
in the body to carry oxygen to the tissues. Disc-shaped red blood
cells contain a molecule called hemoglobin which is important in
oxygenating all the tissues in the body.
These tissues need enough oxygen to ensure their proper functioning
and a short supply has widespread effects on the general health
including weakness, fatigue, tiredness and breathlessness on minor
effort. When a person has anemia, the skin may be very pale and
there will be lowered resistance to infection.
What Causes Anemia?
Anemia can occur for many different reasons including
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Any process that destroys the red blood cells in the body.
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Any excessive blood loss from the body
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Insufficient production of red blood cells by the bone marrow
Anemia can also occur due to inherited disorders but in most cases
it is caused by changes in the state of the body from environmental
impacts like nutritional problems, infection, or exposure to drugs
or toxic substances.
Types of Anemia and Their Causes
Anemia Caused by Destruction of Red Blood Cells
Hemolytic Anemia
When red blood cells are destroyed before they mature and the bone
marrow (the soft, spongy tissue inside our bones responsible for
making new red blood cells) is unable to keep up with the demand for
cells and oxygen from the body it causes a condition called
hemolytic anemia.
Hemolytic anemia may occur for a number of different reasons, for
example an infection in the body or exposure to certain medications
(including those used in chemotherapy and radiation), antibiotics or
medications used to treat epilepsy.
There are several different kinds of hemolytic anemia:
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Autoimmune hemolytic anemia occurs when the immune system mistakenly
identifies red blood cells as foreign invaders and starts to attack
and destroy them.
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Inherited hemolytic anemias include sickle cell anemia, thalassemia,
and glucose-6-phosphate dehydrogenase deficiency.
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Sickle cell anemia is a severe form of hemolytic anemia that occurs
in people of African heritage but it is also found in Caucasian,
Saudi Arabian, Indian, and Mediterranean individuals. The hemoglobin
in the blood of a person with sickle cell anemia forms long rods as
it releases oxygen, and the red blood cells are stretched into
abnormal ‘sickle’ shapes.
The red blood cells are destroyed too soon and the amount of
hemoglobin in the blood becomes very low causing episodic pain.
Sickle cell anemia is especially dangerous during pregnancy (see
‘Anemia Associated with Pregnancy’ below).
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Thalassemia is another form of hemolytic anemia that occurs in
people of Mediterranean, African, and Southeast Asian descent.
Thalassemia causes the life span of red blood cells to become
shortened. Thalassemia ‘major’ is a very severe kind of anemia where
the blood cells are quickly destroyed and iron is deposited in the
skin and vital organs.
Anemia Caused by Blood Loss
When abnormal blood loss occurs in the body such as from excessive
bleeding, injury, surgery, or a problem with the blood's clotting
mechanism, anemia may result. This blood loss does not need to be
dramatic, however, and slower, long-term blood loss, for example
from intestinal bleeding from inflammatory bowel disease, can also
contribute to the development of this kind of anemia. Anemia may
even result from very heavy menstrual bleeding in women.
Anemia Caused by Inadequate Red Blood Cell Production
When the body isn't able to make new, healthy red blood cells due to
a deficiency of, for example, iron, vitamin B12 or folic acid, or
from inherited defects or diseases that interfere with the
production of red blood cells, anemia will result. There are several
different kinds of anemia caused by inadequate red blood cell
production.
Iron Deficiency Anemia
The body needs iron to make the hemoglobin in red blood cells. If
there is insufficient iron in the body due to a poor diet or
excessive iron loss from illness, disease or certain medications
iron-deficiency anemia will result.
This is the most common form of anemia and occurs in 20% of women,
50% of pregnant women (see ‘Anemia Associated with Pregnancy’
below), and 3% of men. The food we eat should provide us with
adequate amounts of iron and the rest is obtained from recycling
iron from old red blood cells. Insufficient iron leads to the blood
being unable to carry oxygen properly and every cell in the body is
affected.
If the normal stores of iron in the body are used up and the bone
marrow and iron is not replaced anemia starts to develop. Women have
smaller stores of iron than do men and lose more through
menstruation – so they are at higher risk for developing this form
of anemia.
Certain kinds of cancer can lead to the development of
iron-deficiency anemia foe example those of the esophagus, stomach
and colon.
Symptoms you may experience with iron-deficiency anemia are:
How is It Treated?
Oral iron supplements may be taken by mouth as ferrous sulfate and
are best absorbed on an empty stomach. Some people find this
irritating and will need to take it with food. Milk and antacids can
interfere with iron absorption but vitamin C increases absorption
and helps produce hemoglobin in the red blood cells. In severe cases
iron deficiency anemia may need to be treated by a blood
transfusion.
Iron may also be supplemented by intavenous or intra-muscular
injection.
Once the iron supplies in the body are boosted the blood should
return to normal within two months but iron should still be
supplemented for another 6 to 12 months to make sure the bone marrow
is replenished.
There aren’t usually any long-term complications to iron-deficiency
anemia but follow-ups should be done as it can recur.
To prevent an iron deficiency you should include red meat, liver,
egg yolks, flour, bread, and cereals fortified with iron in your
daily diet.
Folate Deficiency Anemia
Folate deficiency anemia occurs when there is not enough folic acid
in the body to form and grow new blood cells. Folate is not stored
by the body and it needs to be consumed in food every day.
Medications that interfere with the absorption of folic acid can
cause this kind of anemia. Folate deficiency is a common
complication of pregnancy (see ‘Anemia Associated with Pregnancy’
below).
When there is not enough folic acid in the body, the red blood cells
become abnormally large and are referred to as megalocytes. If they
are in the bone marrow they are called megaloblasts. This type of
anemia may also be referred to as megaloblastic anemia
Folate deficiency causes several effects on the body for example:
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Tiredness
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Headache
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Sore mouth and tongue
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Pallor
How is It Treated?
The aim of treatment is to treat the underlying cause which may be
dietary or a malabsorption disease or the action of certain
medications on the body such as in chemotherapy.
Oral or intravenous folic acid supplements can also be taken for a
short period until the anemia has been addressed but if poor
absorption by the intestine is the cause, replacement therapy may
have to be taken for life.
Increasing the intake of green leafy vegetables and citrus fruits
may help to prevent folate deficiency anemia and are a good general
measure for those with the tendency towards such a deficiency.
The illness responds well to treatment with folic acid supplements
within two months.
Vitamin B12 Deficiency Anemia
Vitamin B12 deficiency anemia occurs when the number of red blood
cells drops due to insufficient amounts of B12 in the body. This may
be due to a diet that does not contain enough vitamin B12, chronic
alcoholism, abdominal or intestinal surgery, Crohn’s disease and
malabsorption disorders.
The symptoms of vitamin B12 deficiency anemia may include:
How is It Treated?
Anemia caused by a lack of vitamin B12 can be addressed by a
well-balanced diet or the use of vitamin B12 injections, especially
after surgeries known to cause vitamin B12 deficiency. If diagnosed
and treated early the severity of this anemia can be prevented.
Aplastic Anemia
If the bone marrow can’t produce sufficient numbers of blood cells,
due to illness, it can cause a condition called aplastic anemia.
Aplastic anemia can be caused by a virus infection or exposure to
certain toxic chemicals, radiation, or medications, such as
antibiotics, anti-seizure medications, or medications used to treat
cancer (such as those used in chemotherapy). Cancers that damage the
kidneys or thyroid can also cause this kind of anemia.
Anemia Associated with Pregnancy
Pregnancy may cause anemia. In fact it is the most common
hematologic complication of pregnancy. When a woman is pregnant the
blood plasma volume increases by approximately 45 percent and
increases as high as 80 percent have been reported.
There are several different kinds of anemia associated with
pregnancy:
Iron Deficiency Anemia
Approximately 75 to 95 percent of all cases of anemia that occur
during pregnancy fall into this category.
Iron constitutes lower than 0.01 of 1 percent of the body's total
weight but it is vitally important to transport oxygen and carbon
dioxide, in the body, aids in the production of red blood cells, and
boosts the immune system response.,
Two-thirds of the iron in the body is found in the molecules of
hemoglobin, transferrin, serum ferritin and myoglobin. Stored iron
makes up the rest of the body’s iron.
During pregnancy a total of 1 g of iron is required initially but
this increases from 1.5 to 2 mg per day to 5 to 7 mg per day by the
late second trimester and during the third trimester.
About 50% of the iron is needed for the mother’s increased blood
volume and the rest is used for the growth of the baby and the
placenta or is lost by means of the increased excretion that occurs
during pregnancy.
Like all iron-deficiency anemias (see above) the iron stores slowly
become depleted and the bone marrow will not have enough iron to
produce healthy hemoglobin molecules. As the hemoglobin levels drop
the hemoglobin and hematocrit levels fall below normal, and the red
blood cells can’t carry enough oxygen to the tissues of the body.
There may be breathlessness, a pale skin, palpitations and
tachycardia.
If the condition is left untreated the symptoms may become worse
with difficulty swallowing, anorexia, a sore mouth or tongue,
decreased cold tolerance, paresthesia, headache, fainting, ringing
in the ears and/or irritability.
How is it treated?
The iron levels in the blood must be replenished and early
administration of pre-natal vitamins and iron is recommended daily
since it isn’t possible to get enough for both mother and baby from
food alone especially when they have been depleted.
The taking of iron supplements does have risks, for example giving
oral iron supplements exceeding 100 mg per day can cause mild liver
damage and a decrease in serum zinc levels that are thought to cause
some fetal abnormalities. This may be addressed by supplementing
zinc.
The Centers for Disease Control and Prevention (CDC) and the
American Dietetic Association recommend 30 to 60 mg of elemental
iron supplementation per day. The American College of Obstetricians
and Gynecologists recommends 30 mg of elemental iron per day during
the second and third trimesters.
Once treatment is begun the hemoglobin levels in the blood start to
normalize within three weeks. Blood tests may be taken at two to
four week intervals to make sure that the supplementation is
working.
Folate Deficiency Anemia
Folic acid is a water-soluble vitamin that helps to make DNA and
protein in the body. During pregnancy this vitamin may become
depleted because of increased demands from the mother and baby.
Pregnant women need at least 150 [mu]g of folic acid per day and
deficiencies are usually caused by inadequate nutrition during
pregnancy.
Certain drugs may also cause a deficiency of this valuable vitamin
such as phenytoin, ethanol, barbiturates, nitrofurantoin and
trimethoprim. Women who are expecting twins may have an increased
need over and above the norm. Bowel disorders, such as ulcerative
colitis and Crohn's disease and women with closely spaced
pregnancies may also develop a deficiency.
Folic acid deficiency may cause negative effects on both the mother
and baby and these inlcude abruptio placenta, pregnancy-induced
hypertension, low birth weight and premature birth, open neural tube
defects.
How is it Treated?
Pre-natal vitamins can be bought without a prescription and contain
0.8 mg of folic acid or a doctor can prescribe prenatal vitamins
that contain 1.0 mg of folic acid. Taking these supplements will
provide enough folic acid to prevent and treat folic acid deficiency
in pregnant women. If 0.4 mg is taken daily it can prevent up to 50
percent of the 2,500 cases of open neural tube defects that occur in
the United States every year.
The Center for Disease Control and the United States Public Health
Service, advises all women of childbearing age to consume 0.4 mg of
folic acid per day to reduce the risk of delivering babies with open
neural tube defects. A high dose (4.0 mg daily) of folic acid should
be taken at least one month prior to conception and continued for
the first three months in women who have given birth to babies with
these problems in the past.
Glucose-6-Phosphate Dehydrogenase Deficiency
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked
erythrocyte enzyme deficiency that can be passed on to male children
of female carriers. The mothers are usually not affected but may
show symptoms when given oxidizing drugs such as sulfonamides,
nitrofurantoin, primaquine, large doses of vitamin K and/or severe
viral or bacterial infections.
'Type A' is found in African American patients, and the
Mediterranean type, found in patients of Greek, Sephardic Jewish and
Sardinian ancestry, are common.
Blood tests reveal a low hematocrit or hemoglobin level and a low
erythrocyte count in the absence of iron deficiency anemia, or
presumed iron deficiency anemia that is unresponsive to treatment.
Sickle Cell Anemia
Approximately 8 percent of African Americans show the markers for
sickle cell anemia. When a woman becomes pregnant they can becom ill
with with sickle cell disease. Sickle cell anemia is a type of
hemolytic anemia in which the hemoglobin in the blood forms long
rods as it releases oxygen, and the red blood cells are stretched
into abnormal sickle shapes. The red blood cells are destroyed too
soon and the amount of hemoglobin in the blood becomes very low
causing episodic pain and a variety of other symptoms.
All pregnant women who are at risk for sickle cell anemia should be
screened with a sickledex. If the test is positive it will then be
established if she is only a carrier or actually has the disease.
The patient’s partner is also tested to see if he is a carrier. From
this doctors can determine the risk to the unborn baby.
How is it Treated?
Genetic counseling should be given to couples who both carry the
sickle cell trait as 50% of babies born to these parents do inherit
the trait. Twenty-five percent of babies will be born with sickle
cell disease and 25 percent will be normal. Sickle cell disease can
be detected using amniocentesis, chorionic villus sampling or
chordocentesis.
Because rates of premature birth, low birth weight and other
complications are increased in sickle cell anemia patients are
treated by specilaists in the disease to avoid any negative effects
on the mother and baby which may be serious.
Expectant mothers are usually given folic acid supplements to help
manage the disease.
Whatever type of anemia you have it is important that you obtain
prompt and correct treatment to make sure that your red blood cells
are able to feed the tissues of your body and keep you healthy. If
you experience any of the above symptoms talk to your doctor and
make sure that adequate steps are taken to prevent illness and
restore you to good health.
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