Laboratory Screening for Anemia: Hematological Assessment and Diagnostic Evaluation-An Updated Review

Background: Anemia is a common hematological condition characterized by reduced hemoglobin concentration or circulating red blood cell mass. It represents an important clinical and public health concern because it can impair tissue oxygenation, worsen underlying diseases, and indicate several nutritional, genetic, infectious, and systemic disorders. Early detection and accurate diagnosis are essential for appropriate management. Aim: This review aims to provide an overview of anemia screening, focusing on its etiology, epidemiology, pathophysiology, diagnostic investigations, interpretation of laboratory findings, and laboratory quality and safety requirements. Methods: A narrative review was conducted covering the principal mechanisms and causes of anemia, its distribution across different populations, the physiological regulation of erythropoiesis, and the laboratory approaches used for screening and diagnosis. Relevant investigations, transfusion considerations, quality assurance procedures, and laboratory safety practices were also discussed. Results: Anemia develops primarily through decreased red blood cell production, increased red blood cell destruction, or blood loss. Its prevalence varies according to geographical, demographic, genetic, nutritional, and socioeconomic factors. Initial screening relies on complete blood count parameters, including hemoglobin, hematocrit, and red blood cell indices. Reticulocyte count, peripheral blood smear, iron profile, vitamin B12, folate, and targeted biochemical investigations support etiological classification. Additional immunological, genetic, imaging, and bone marrow investigations may be required in selected cases. Accurate results depend on appropriate specimen handling, internal and external quality control, and adherence to laboratory safety standards. Conclusion: Systematic laboratory screening facilitates early anemia detection, identification of underlying causes, and appropriate clinical management.