Definition
Anemia is a condition with decreased red blood cells (RBCs) or hemoglobin (Hb), reducing oxygen-carrying capacity and causing fatigue, weakness, and dyspnea.
Types of Anemia
1) Based on RBC Size (MCV):
Microcytic (MCV < 80 fL): Iron deficiency, thalassemia, sideroblastic anemia.
Normocytic (MCV 80–100 fL): Acute blood loss, chronic disease, hemolysis.
Macrocytic (MCV > 100 fL): Vitamin B12/folate deficiency, alcoholism, liver disease.
2) Based on Pathophysiology:
Iron Deficiency: Low iron levels, most common type.
Megaloblastic: Impaired DNA synthesis (B12/folate deficiency).
Hemolytic: Premature RBC destruction (autoimmune, hereditary).
Aplastic: Bone marrow failure (pancytopenia).
Chronic Disease: Linked to inflammation or cancer.
Sickle Cell: Genetic, abnormal HbS causing sickled RBCs.
Thalassemia: Genetic, defective hemoglobin synthesis.
Causes
Blood Loss:
Acute (trauma, surgery).
Chronic (menorrhagia, GI bleeding).
Reduced RBC Production:
Nutritional deficiencies (iron, B12, folate).
Bone marrow failure (aplastic anemia, leukemia).
Chronic diseases (kidney disease).
Increased RBC Destruction (Hemolysis):
Autoimmune diseases, infections, genetic disorders.
Symptoms
Fatigue, weakness, pallor.
Dyspnea, dizziness, palpitations.
Cold extremities, headaches, chest pain (severe cases).
Restless legs syndrome (iron deficiency).
Diagnosis
Blood Tests:
CBC: Low Hb, Hct, and MCV.
Reticulocyte Count: Bone marrow activity.
Iron Studies: Serum iron, ferritin, TIBC.
Vitamin Levels: B12, folate.
Hemolysis Markers: LDH, bilirubin, haptoglobin.
Specialized Tests:
Bone Marrow Biopsy: Aplastic anemia.
Electrophoresis: Sickle cell, thalassemia.
Coombs Test: Autoimmune hemolysis.
Treatment
Nutritional Deficiencies:
Iron Deficiency: Oral/IV iron, diet changes.
B12 Deficiency: Oral/injections.
Folate Deficiency: Oral supplements.
Blood Transfusions:
Severe anemia (Hb < 7–8 g/dL).
Underlying Causes:
Chronic kidney disease: Erythropoietin therapy.
Aplastic anemia: Immunosuppressants or bone marrow transplant.
Hemolytic anemia: Steroids, immunosuppressants, splenectomy.
Genetic Disorders:
Sickle Cell Disease: Hydroxyurea, bone marrow transplant.
Thalassemia: Blood transfusions, iron chelation.
Complications
Severe Fatigue: Affects quality of life.
Heart Problems: Tachycardia, heart failure.
Growth Delay: In children.
Pregnancy Risks: Preterm birth, low birth weight.
Organ Damage: Due to prolonged hypoxia.
Prognosis
Mild Cases: Often reversible.
Severe Cases: May need long-term monitoring.
Genetic Disorders: Require lifelong care.