Introduction
Anemia is a condition in which the body is severely
deficient of healthy red blood cells which have the ability to carry oxygen to
different parts of body.
Anemia affects almost 1.62 billion people on earth, which
means that 24.8% of the Earth's total population is anemic. It is most
prevalent in children of pre schooling age and the least prevalent in men. The
population group with the highest number of effected individuals is the
non-pregnant women (468.4 million).
Types of Anemia and their causes
Anemia is of different types and they may have a number of
different causes. The major causes of different types of anemia are explained
as follows:
Iron deficiency anemia:
Iron deficiency anemia is the most common type of anemia and
as the name suggests, it is cause by the lack of sufficient amount of iron in
the body. Iron is important in the synthesis of hemoglobin in the bone marrow.
When the amount of iron is insufficient, enough hemoglobin is not synthesized
and hence the shortage of red blood cells occurs. This type of anemia is common
in pregnant women. It may also occur due to blood loss such as bleeding caused
by an ulcer, cancer, heavy menstruation and over use of some medications such
as NSAIDs (Non-Steroidal Anti Inflammatory Drugs) which cause inflammation of
the lining of stomach causing ulcer.
Vitamin deficiency anemia:
Along with iron, vitamin B-12 and folate are essential for
the production of enough amounts of healthy red blood cells. Consumption of a
diet in which these nutrients are deficient cases decreased production of RBCs.
Some people who take enough vitamin B-12 but aren't able to consume it, also
develop Vitamin deficiency anemia. Such type of anemia is known as pernicious
anemia.
Anemia caused due to inflammation:
Diseases such as cancer, HIV/AIDS, rheumatoid arthritis,
renal diseases, Crohn's diseases and many other acute and chronic diseases, can
affect the normal production of red blood cells.
Aplastic Anemia:
This rarely occurring, life threatening anemia occurs when
the body is not able to produce enough amounts of red blood cells. Causes of
aplastic Anemia could be microbial infections, certain medications, autoimmune
diseases and exposure to toxic substances.
Anemia caused by defects in bone marrow:
Red blood cell production could be effected by a variety of
diseases occurring in bone marrow such as leukemia and myelofibrosis, leading
to the development of anemia. These cancer and cancer-like conditions could be
mild and sometimes, life-threatening.
Sickle cell anemia:
Sickle cell Anemia is a hereditary disease which causes
hemolysis of Red blood cells. It is caused by a defect in hemoglobin which
causes the red blood cells to acquire an abnormal shape that resembles a sickle
or crescent. Due to their abnormal shape, the cells die before getting mature,
therefore causing a shortage of RBCs.
Life cycle of RBCs
In the bone marrow, burst forming units-erythroid (BFU-E)
and colony forming units-erythroid (CFU-E) are differentiated into
reticulocytes. This differentiation is enhanced by erythropoietin.
Reticulocytes stay in the bone marrow for three months to
get mature after which they move into peripheral blood.
Mature RBCs then circulate in the peripheral blood for 100
to 120 days (approximately 4 months).
In the state of equilibrium or under steady state
concentration, the rate of production of RBCs equals the rate of loss of RBCs.
Lab definition
Hemoglobin (Hgb);
Women:
Men:
Hematocrit (Hct);
Women:
Men :
< 41
Lab findings
Iron deficiency anemia;
Serum iron
Low (<60 micro grams/dL)
Total iron binding capacity (TIBC)
High (>360 micrograms/dL)
Serum Ferritin
Low (<20 Nano grams/mL)
It could be 'falsely' normal in inflammatory conditions
Symptoms
Different symptoms of Anemia that appear due to decreased
oxygenation of body tissues and decreased supply of blood are as follows:
Symptoms that appear due to decreased oxygenation:
Exertional dyspnea
Dyspnea at rest
Fatigue
Bounding pulses
Lethargy
Confusion
Symptoms that appear due to decreased volume of blood:
Fatigue
Muscular cramps
Postural dizziness
Syncope
Special considerations while diagnosing anemia
Acute bleeding:
Drop in hemoglobin (Hgb) or hematocrit (Hct) is not observed
until 36 to 48 hours of after acute bleeding has occurred (even though the
patient may be hypotensive)
Pregnancy:
In the third trimester of pregnancy, the RBCs and plasma
levels are expanded by 25 and 50%, respectively.Lab findings will show a
reduction in hgb, hct, and the RBC count often to anemic levels, but according
to the RBC mass, they are actually polycythemic
Volume Depletion:
Patients with severe volume Depletion may not show anemia
until after they are re-hydrated.
Complications
If left untreated, anemia can develop into severe and
complicated health conditions such as:
Severe fatigue:
Anemia at chronic stages causes extreme tiredness and
fatigue, making it impossible to perform daily life activities.
Complications in pregnancy:
Folate deficiency anemia in pregnant women can cause
complications such as premature birth.
Cardiovascular problems:
When an individual is anemic, his/her heart must pump enough
blood to fulfill the oxygen requirement of the body. This can lead to the
enlargement of heart or cardiac failure. Anemia can also cause arrhythmia.
Death:
Anemia such as sickle cell anemia could be fatal. Loss of a
lot of blood abruptly causes acute or severe anemia or even death
Prevention
Many types of Aneamias such as those inherited from parents,
are not preventable. Iron and vitamin deficiency could be prevented by taking a
diet that includes a number of vitamins and essential minerals, including:
Iron:
Food rich in iron includes beef and meat, red beans,
lentils, cereals fortified with iron, green leafy vegetables and dry fruit.
Folate:
Folate is found in fruits and their juices, leafy
vegetables, peas, kidney beans, peanuts, enriched grains, bread, pasta,
fortified cereals and rice.
Vitamin B-12:
Foods containing sufficient amount of vitamin B12 include
meat, milk, yogurt, butter and other dairy products, fortified and enriched
cereals and grains, soy products.
Vitamin C:
Vitamin C is present in citrus fruits and juices, peppers,
broccoli, tomatoes, melons and strawberries. They help in the absorption of
iron.
(Consult your doctor or nutritionist to guide you about the
diet suitable for preventing anemia).
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