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Overview |
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Definition |
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Anemia is characterized by a reduction in either the hematocrit (red blood
cell [RBC] volume <42% in men and <36% in women) or the concentration of
hemoglobin (<14 g/dL in men and <12 g/dL in women). The prevalence of
anemia is highest among menstruating women (5.8%), infants (5.7%), and the
elderly (12%). Anemias can be distinguished morphologically based on the size of
the RBCs or the mean corpuscular volume.
- Microcytic anemias are characterized by small RBCs (mean corpuscular
volume <80 fL) and include iron-deficiency anemia, anemia of chronic disease,
thalassemias, and sideroblastic anemias.
- Macrocytic anemias are characterized by large RBCs (mean corpuscular
volume >98 fL) and include megaloblastic anemias (e.g., from vitamin B12
[pernicious anemia] and folic acid deficiencies), myelodysplastic anemias (e.g.,
from cancer chemotherapy), and liver disease (e.g., alcoholism).
- Normocytic anemias are characterized by RBCs within the normal size
range (mean corpuscular volume, 80 to 98 fL) and include anemias of acute blood
loss, acquired and inherited hemolytic anemias (e.g., sickle-cell anemia), mixed
micro-macrocytic anemias, and anemias related to renal failure and bone marrow
disease.
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Etiology |
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Anemia is caused by decreased production of RBCs resulting from deficiencies
in the elemental ingredients necessary for RBC production, by increased
destruction of RBCs (hemolysis) from defects in the RBC or environmental
stressors, and from excessive bleeding.
Decreased production of RBC is caused by the following.
- Menstruation (monthly iron losses, 20 to 30 mg/month)
- Pregnancy (iron losses from increased needs and losses at the time of
delivery) and lactation
- Iron, folic acid, vitamin B12, or erythropoietin
deficiencies
- Chronic disease states (e.g., rheumatoid arthritis, inflammatory
bowel disease, renal failure)
- Inherited anomalies (e.g., thalassemias)
- Gastrointestinal blood loss (e.g., ulcers, cancer,
parasites)
- Genitourinary blood loss (e.g., pregnancy, uterine bleeding,
menstruation)
- Overt blood loss (e.g., after surgery, chronic ingestion of
nonsteroidal anti-inflammatory drugs [NSAIDs], or regular blood
donations)
- Malabsorption syndromes (e.g., celiac disease)
- Neoplasia
- Alcohol ingestion
Increased destruction of RBC is caused by the following.
- Inherited anomalies (e.g., membrane, enzyme, or hemoglobin
anomalies)
- Environmental stresses (e.g., antibody deposition, parasitic
infection)
- Oxidant drugs (e.g., antibiotics, antimalarials,
analgesics)—specific to patients with
glucose-6-phosphate dehydrogenase (G6PD)
deficiency
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Risk Factors |
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- Family history of anemia
- African-American with G6PD deficiency
- Mediterranean ancestry (thalassemia)
- Women in the reproductive years
- Inflammatory disease or advanced malignancy
- Drugs that injure the gastric or intestinal mucosa
- Parasitic infestation (e.g., malaria and babesiosis)
- Malnutrition
- Alcoholism
- Low-income elderly with poor
diets
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Signs and Symptoms |
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There is tremendous variability among individuals in the clinical
manifestations of anemia, which depend on the cause, severity, onset, and any
underlying disease process. Generally symptoms occur when there is an acute drop
in hemoglobin to 7 to 8 g/dL. However, if anemia develops slowly, patients may
be able to tolerate hemoglobin levels as low as 6 to 7 g/dL before becoming
symptomatic.
- Fatigue
- Headache
- Dyspnea (shortness of breath)
- Lightheadedness
- Pain in the abdomen and back
- Palpitations and angina
- Episodic jaundice and dark urine (i.e.,
hemoglobinuria)—specific to sideroblastic
anemia
- Pica (cravings for strange foods) and koilonychia (thin, concave
nails)—specific to iron-deficiency anemia
- Glossitis, jaundice, loss of vibratory and position sense, and
neurologic symptoms, which may be permanent—specific to
pernicious anemia (i.e., vitamin B12
deficiency)
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Differential
Diagnosis |
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Many disorders, including congestive heart failure and
hypersplenism. |
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Diagnosis |
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Physical Examination |
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Because anemia is often the result of an underlying disease process, the
history and physical examination are extremely important. Anemic patients are
often pale and may appear confused, frail, unsteady, and short of breath. The
presenting symptom may be chest pain or syncope. Vital sign abnormalities
include hypotension or tachycardia. Anemia is defined by the laboratory values
and these values and the clinical picture are necessary for a definitive
diagnosis. |
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Laboratory Tests |
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- Complete blood count (CBC)
- Peripheral blood smear
- Reticulocyte count
- Stool for occult blood
- Serum iron studies
- Platelet count
- Blood test for B12 and folic
acid
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Pathology/Pathophysiology |
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- Low, normal, or high mean corpuscular volume defines microcytosis,
normocytosis, or macrocytosis, respectively.
- Poilkilocytosis (abnormal variation in shape of RBCs) as described by
the red cell distribution width
- Hypochromia (decreased hemoglobin content of RBCs)
- Reticulocytosis (increased number of reticulocytes [immature RBCs])
is an important distinguishing characteristic of hemolytic anemia.
- A decreased number of reticulocytes is an important distinguishing
characteristic of hypoproliferative anemia.
- Iron accumulation is specific to sideroblastic anemia.
- Low serum iron is specific to iron deficiency anemia.
- Pancytopenia.
- Sickled RBCs are specific to sickle-cell anemia.
- Elevated blood urea nitrogen and serum creatinine are specific to
anemia of chronic renal failure.
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Imaging |
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May need abdominal sonogram to check spleen size. |
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Other Diagnostic
Procedures |
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- Coulter counter (for CBC)
- Radioimmunoassay (to measure vitamin B12 levels)
- Bone marrow examination
- Gene mapping for alpha and beta chains (for thalassemias) and for
sickle-cell disease
- Schilling test
- Coombs antiglobulin test
- Hemoglobin electrophoresis
- Erythrocyte sedimentation rate
- Creatinine levels
- Liver function tests
- Thyroid profile
- GI exam for source of
bleeding
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Treatment Options |
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Treatment Strategy |
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Therapy for anemia depends on the cause and the severity of the anemia. In
some anemias, the therapy is well established; in others the therapy is largely
expectant, depending on the successful treatment of the underlying disease
(e.g., anemia of chronic disease). Avoid oxidant medications in patients with
G6PD deficiency.
Other treatment options include the following.
- Supportive care (e.g., transfusions), folic acid, and
fluids—for patients with sickle cell anemia
- Supportive care (e.g., transfusions), symptomatic therapy, bone
marrow transplantation, and splenectomy—for the alpha
and beta thalassemias
- Splenectomy—for hereditary
spherocytosis
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Drug Therapies |
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- Erythropoietin plus iron—for anemia of
chronic renal failure
- Steroids (e.g., prednisone), splenectomy, cytotoxic agents (e.g.,
azathioprine), or transfusions—for autoimmune hemolytic
anemia
- Analgesics (for painful crises)—for
sickle-cell anemia
- Cessation of offending drugs—for acquired
forms of sideroblastic anemia
- Iron replacement
- Transfusions
- Treatment of underlying
disorders
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Complementary and Alternative
Therapies |
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Most cases of macrocytic and microcytic anemias may respond well to
nutritional therapy. Patients need to be counseled that excess iron is toxic and
should not be taken unless indicated by abnormal lab values. Herbal and dietary
treatments may be helpful as adjunctive. |
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Nutrition |
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- Ferrous fumerate, glycerate or glycinate (100 mg/day for three to six
months) are the most absorbable forms of iron. Ferrous sulfate (325 mg/day) is
poorly absorbed and more frequently causes problems with GI upset and/or
constipation. Dietary sources of iron include meat, beans, green leafy
vegetables, beet greens, blackstrap molasses, almonds, and brewer's
yeast.
- Vitamin C—for pernicious anemia, up to 1,000
mg tid will aid in absorption of iron.
- Vitamin B12—cyanocobalamine, 1,000 IU
intramuscular injection bid for one week, then weekly for one month, then every
two to three months. (Note that dosing varies depending on individual case.)
Dietary sources include organ meats, meats, eggs, fish, and cheese.
- Folic acid (1 to 2 mg/day)—for folic acid
deficiency and hereditary spherocytosis. Good food sources include green leafy
vegetables and grains.
- Omega-3 and omega-6 essential fatty acids (1,000 to 1,500 IU) have
been shown to decrease the frequency of sickle-cell crisis. EFAs can increase
clotting times so may need to be checked in people on
anticoagulants.
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Herbs |
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Herbs are generally a safe way to strengthen and tone the body's systems. As
with any therapy, it is important to ascertain a diagnosis before pursuing
treatment. Herbs may be used as dried extracts (capsules, powders, teas),
glycerites (glycerine extracts), or tinctures (alcohol extracts). Unless
otherwise indicated, teas should be made with 1 tsp. herb per cup of hot water.
Steep covered 5 to 10 minutes for leaf or flowers, and 10 to 20 minutes for
roots. Drink 2 to 4 cups/day. Tinctures may be used singly or in combination as
noted.
Patients may be treated for one to three months and then
reassessed.
- Blackstrap molasses, also known as pregnancy tea (1 tbsp./day in a
cup of hot water), is a good source of iron, B vitamins, minerals, and is also a
very gentle laxative.
- Spirulina, or blue-green algae, has been used successfully to treat
both microcytic and macrocytic anemias. Dose is 1 heaping tsp./day.
- Alfalfa (Medicago sativa), dandelion (Taraxacum officinale)
root or leaf, burdock (Arctium lappa), and yellowdock (Rumex
crispus) have long been used to fortify and cleanse the blood. For mild
cases of anemia, they may help to bring lab values into normal range. Dosage is
1 tbsp./cup of water. Simmer roots for 20 minutes and leaves for 5 minutes. A
single herb, or a combination of these four herbs, may be
used.
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Homeopathy |
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An experienced homeopath should assess individual constitutional types and
severity of disease to select the correct remedy and potency. Use Ferrum
phosphoricum 12C once a day for iron deficiency
anemia. |
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Patient Monitoring |
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The frequency of checking the CBC for anemia depends on its cause and
severity. Patients should be counseled to maintain a normal balanced diet
containing all of the nutrients necessary for blood formation and on the
potential adverse gastric effects of certain drugs. Vegetarians need to pay
close attention to sources of vitamin B12 and iron, and may need to take
supplements. |
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Other
Considerations |
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Prevention |
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It can take three to five years to develop a vitamin B12 deficiency. Folic
acid is more rapidly depleted, and deficiency can manifest within a few months.
B12 requires sufficient hydrochloric acid for proper utilization. Macrocytic
anemia treated with only folate may mask a B12
deficiency—leading to rare cases of permanent nerve
damage. Therefore, B12 should be given with folate. |
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Complications/Sequelae |
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Complications for anemia can range from loss of productivity due to weakness
and fatigue to myocardial infarction and death. |
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Prognosis |
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The expected course and prognosis is dependent on the type of anemia and the
treatment. |
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Pregnancy |
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Pregnant women need three to four times as much iron as normal (10 mg/day);
thus, the increased demands of pregnancy and blood loss at the time of delivery
can lead to iron-deficiency anemia (iron, B12, and/or folate). Iron-deficiency
anemia can result in premature labor, post-partum hemorrhage, low-birth-weight
infants, perinatal mortality and can contribute to post-partum depression. A
folic acid deficiency during pregnancy, but most importantly in the three months
prior to conception, increases the risk of neural tube defects in the
infant. |
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References |
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Branch WT Jr. Office Practice of Medicine. Philadelphia, Pa: WB
Saunders Company; 1994.
Fauci AS, Braunwald E, Isselbacher KJ, et al., eds. Harrison's Principles
of Internal Medicine. 14th ed. New York, NY: McGraw-Hill; 1998.
Kelley WN, ed. Textbook of Internal Medicine. 3rd ed. Philadelphia,
Pa: Lippincott-Raven; 1997.
Tyler VE. The Honest Herbal: A Sensible Guide to the Use of Herbs and
Related Remedies. 3rd ed. Binghamton, NY: Pharmaceutical Products Press;
1993. |
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Copyright © 2000 Integrative Medicine
Communications This publication contains
information relating to general principles
of medical care that should not in any event be construed as specific
instructions for individual patients. The publisher does not accept any
responsibility for the accuracy of the information or the consequences arising
from the application, use, or misuse of any of the information contained herein,
including any injury and/or damage to any person or property as a matter of
product liability, negligence, or otherwise. No warranty, expressed or implied,
is made in regard to the contents of this material. No claims or endorsements
are made for any drugs or compounds currently marketed or in investigative use.
The reader is advised to check product information (including package inserts)
for changes and new information regarding dosage, precautions, warnings,
interactions, and contraindications before administering any drug, herb, or
supplement discussed herein. | |