Anemia Overview

1. Definition

Anemia is a condition characterized by a lower-than-normal number of red blood cells or hemoglobin (Hb) levels in the blood compared to individuals of the same age, gender, health status, and living conditions (lowlands, mountainous regions). This leads to a decreased capacity of the blood to transport oxygen, resulting in oxygen deficiency in tissues and organs throughout the body.

2. Anemia Classification

Anemia can be classified according to various criteria, aiding in determining the cause and guiding effective treatment:

a) By Severity:

• Mild Anemia: Hb from 9 – 10.9 g/dL.

• Moderate Anemia: Hb from 7 – 8.9 g/dL.

• Severe Anemia: Hb below 7 g/dL.

Note: Anemia severity is assessed based on Hb levels, but clinical manifestations and other laboratory tests should be considered for a definitive diagnosis.

b) By Progression:

• Acute Anemia: Onset is rapid, often caused by acute blood loss, acute hemolysis, malignancies, etc.

• Chronic Anemia: Onset is gradual, often caused by iron deficiency anemia, vitamin deficiencies, chronic illnesses, etc.

c) By Cause:

• Anemia due to Blood Loss: Due to acute bleeding (accidents, surgery, gastrointestinal bleeding, etc.), chronic bleeding (heavy menstrual bleeding, gastrointestinal disorders, etc.), clotting disorders, etc.

• Anemia due to Hemolysis: Due to premature destruction of red blood cells (genetic disorders like Thalassemias, sickle cell disease, autoimmune diseases, infections, etc.).

• Anemia due to Decreased/Disordered Hematopoiesis: Due to insufficient or abnormal red blood cell production by the bone marrow (malnutrition, lack of raw materials, bone marrow failure, malignancies, etc.).

d) By Red Blood Cell Characteristics:

• MCV (Mean Corpuscular Volume – Average Red Blood Cell Volume):

• Microcytic Anemia (MCV < 80 fl): Commonly seen in iron deficiency anemia, Thalassemias.

• Normocytic Anemia (MCV 80 – 100 fl): Commonly seen in acute blood loss anemia.

• Macrocytic Anemia (MCV > 100 fl): Commonly seen in vitamin B12 deficiency anemia, folic acid deficiency anemia.

• MCH (Mean Corpuscular Hemoglobin – Average Hb Amount in Red Blood Cells):

• Hyperchromic Anemia (MCH high): Commonly seen in macrocytic anemia.

• Normochromic Anemia (MCH normal): Commonly seen in normocytic anemia.

• Hypochromic Anemia (MCH low): Commonly seen in microcytic anemia.

• MCHC (Mean Corpuscular Hemoglobin Concentration – Average Hb Concentration in Red Blood Cells):

• Low MCHC: Commonly seen in iron deficiency anemia, Thalassemias.

• RDW (Red Blood Cell Distribution Width – Red Blood Cell Size Variability):

• High RDW: Commonly seen in iron deficiency anemia, Thalassemias, bone marrow failure.

• Reticulocytes:

• Reticulocytes present in peripheral blood:

• Compensatory response to anemia, bone marrow releases reticulocytes to replenish blood.

• If anemia persists, and the bone marrow does not release reticulocytes, it indicates bone marrow instability.

Note: Classifying anemia based on red blood cell characteristics is crucial for diagnosing the underlying cause of anemia.

3. Clinical Manifestations

Anemia symptoms usually appear when anemia is severe:

• Pallor: Due to decreased Hb in the blood, the skin becomes oxygen-deficient, leading to paleness, particularly in the mucous membranes, palms, and soles.

• Coldness and Numbness in Limbs: Due to poor blood circulation, extremities experience oxygen deprivation, resulting in cold and numb sensations.

• Tachycardia and Dyspnea: The body compensates for oxygen deficiency by increasing cardiovascular activity, causing rapid heart rate and difficulty breathing.

• Headache, Dizziness, Fatigue: Due to brain oxygen deficiency.

• Sleep Disturbances, Nausea: Due to the impact of oxygen deprivation on the central nervous system.

4. Common Causes

a) In Newborns:

• Twins.

• Premature infants, low birth weight.

• Umbilical cord bleeding due to Vitamin K deficiency.

• Hemolysis due to maternal-fetal blood group incompatibility.

• Neonatal infections.

b) In Infants 3 – 6 Months Old:

• Malnutrition.

• Iron deficiency.

• Malignant hematologic disorders.

• Thalassemias.

c) In Children 5 Years and Older:

• Hookworm infection.

• Bone marrow failure.

• Malignant hematologic disorders.

• Chronic infections.

d) Gender-Related:

• Anemia associated with X-linked disorders: G6PD deficiency, Hemophilia.

e) Other Causes:

• Anemia Onset: Acute (acute bleeding, acute hemolysis), gradual (anemia due to multiple causes, secondary anemia due to systemic disease).

• Nutritional Anemia: Iron deficiency anemia, protein-energy malnutrition, rickets, folic acid deficiency, vitamin B12 deficiency.

• Anemia due to Infection: Anemia due to chronic infection, malaria, chronic hepatitis, tuberculosis.

• Anemia due to Drugs, Toxins: Bone marrow failure, hemolysis.

• Anemia due to Family History: Hemophilia, G6PD deficiency, Thalassemias.

• Anemia due to Trauma: Acute blood loss.

• Anemia due to History of Bleeding: Secondary anemia following blood loss due to thrombocytopenia, clotting disorders, black stools due to hookworm infection, peptic ulcer disease, liver failure.

5. Diagnostic Approach

a) Based on Clinical Manifestations:

• Anemia in newborns accompanied by prolonged umbilical cord bleeding, black stools, neurological-meningeal symptoms –> Suggestive of Vitamin K deficiency anemia.

• Anemia in newborns accompanied by deep jaundice, lethargy, rigidity –> Suggestive of hemolysis due to maternal-fetal blood group incompatibility.

• Anemia in young children, lack of breast milk, malnutrition, prematurity, twins –> Suggestive of iron deficiency anemia, hematopoietic factor deficiency.

• Anemia in older children, abdominal pain, black stools –> Suggestive of hookworm infection.

• Anemia, jaundice, hepatosplenomegaly, dark urine –> Suggestive of hemolytic anemia.

• Anemia, fever with chills, splenomegaly –> Suggestive of malaria.

• Anemia, bleeding, infection –> Suggestive of bone marrow failure.

• Anemia, bleeding, enlarged liver, spleen, lymph nodes, or bone pain, prolonged fever –> Suggestive of acute leukemia.

• Anemia, prolonged fever, signs of infection –> Suggestive of chronic infection.

• Anemia, hypertension –> Suggestive of chronic kidney failure.

b) Based on Laboratory Tests:

• Complete Blood Count (CBC):

• B1. Confirms anemia diagnosis (red blood cell count) and severity based on Hb levels.

• B2. Evaluates MCV, MCH, MCHC, RDW, reticulocytes to determine anemia characteristics.

• B3. Peripheral blood smear for red blood cell morphology assessment.

c) Other Tests:

• G6PD enzyme test.

• Thalassemias testing.

• Bone marrow biopsy.

• Endoscopy of the stomach and duodenum.

• Stool examination for parasites.

Note: Combining clinical manifestations and laboratory test results is essential for accurately diagnosing the cause of anemia.

6. Treatment

• Identifying and Treating the Underlying Cause:

• If iron deficiency anemia, iron supplementation.

• If vitamin B12 deficiency anemia, vitamin B12 supplementation.

• If hemolytic anemia, treating the cause of hemolysis.

• If bone marrow failure, treating bone marrow failure.

• Combining Cause-Specific Treatment with Timely, but Prudent, Red Blood Cell Transfusions: Based on Hb levels and clinical presentation.

• Maintaining Minimum Hemoglobin Levels:

• 80 g/L for healthy individuals.

• 90 g/L for patients with chronic heart and lung diseases.

7. Prevention

• Adequate nutrition, ensuring sufficient iron, vitamin B12, and folic acid intake.

• Iron supplementation for children aged 6 months to 2 years.

• Early detection and treatment of conditions that can cause anemia, such as hookworm infection, malignant hematologic disorders, bone marrow failure, genetic disorders, etc.

• Complete vaccination schedules.

• Regular health checkups.

Note:

• Anemia is a prevalent condition that can occur at any age, particularly in children and pregnant women.

• Timely diagnosis and treatment of anemia help prevent potentially life-threatening complications.

• Consultation with a doctor is necessary for proper advice and treatment.