Red cell distribution width (RDW)

RDW measures the variation in size of red blood cells, helping diagnose and differentiate types of anemia.

📋 About This Biomarker

Red Cell Distribution Width (RDW) measures the variation in the size of red blood cells (RBCs). It is expressed as a percentage and is part of a complete blood count (CBC) test. RDW helps in diagnosing the cause of anemia and other hematologic disorders. A higher RDW value indicates a greater variation in RBC size (anisocytosis), which can result from a mix of normal and abnormal RBCs in the bloodstream. Conditions such as iron deficiency anemia, vitamin B12 deficiency, and folate deficiency often show elevated RDW levels. Conversely, a normal RDW with anemia suggests conditions like chronic disease anemia, where RBCs are uniformly small or large. Understanding RDW values provides insights into RBC production and destruction, helping in the differential diagnosis of various types of anemia and other blood disorders.

🎯 Why We Test This

Assessing RDW levels is crucial for diagnosing and managing different types of anemia and other hematologic disorders. It provides valuable insights into the size variability of RBCs, helping identify the underlying cause of anemia and guiding appropriate treatment. Regular monitoring of RDW levels is important for individuals with symptoms of anemia, chronic diseases, or those undergoing treatments affecting RBC production. Maintaining RDW levels within the normal range is vital for overall blood health and efficient oxygen transport.

⚠️ What Affects It

Factors influencing RDW levels include nutritional deficiencies (iron, vitamin B12, folate), chronic diseases, bone marrow disorders, blood loss, and hemolysis. Certain medications, alcoholism, and inherited conditions like thalassemia can also impact RDW levels.

📈 How to Improve

For high RDW levels, treating the underlying cause, such as nutritional deficiencies (iron, vitamin B12, folate), hemolytic anemia, or bone marrow disorders, is crucial. Ensuring a balanced diet and possibly supplementing with necessary nutrients can help. For levels close to being high, similar dietary adjustments and monitoring are important. For low RDW levels, no specific intervention is typically needed, as they generally do not indicate a clinical problem. However, maintaining overall blood health through a balanced diet and regular check-ups is beneficial. Regular monitoring and consultation with a healthcare provider ensure that RDW levels remain within the optimal range.

📊 Understanding Your Results (%)

Low
Low RDW levels are uncommon and usually not clinically significant. They indicate minimal variation in RBC size, reflecting a homogeneous population of RBCs. Low RDW can occasionally be seen in conditions where the bone marrow produces uniformly small or large RBCs, but it generally suggests no major issues with RBC size variability.
Optimal
Normal RDW levels indicate a uniform size of RBCs, suggesting healthy RBC production and turnover. This balance reflects proper bone marrow function and adequate nutrient supply for red blood cell synthesis. It helps rule out significant variation in RBC size, often associated with specific types of anemia. RDW levels near the upper limit may indicate early or mild nutritional deficiencies or a slight variation in RBC size due to mixed anemia or recent recovery from anemia. Monitoring these levels and addressing any underlying health issues, such as improving dietary intake of iron, vitamin B12, and folate, can help maintain balanced RDW levels. RDW levels near the lower end of the reference range are typically not a cause for concern, as they indicate a low variation in RBC size. This suggests a stable and uniform production of RBCs, often seen in healthy individuals without anemia or related conditions.
High (> 15 %)
Elevated RDW levels indicate a high degree of variation in RBC size. This can suggest conditions like iron deficiency anemia, vitamin B12 or folate deficiency, hemolytic anemia, or mixed anemia (both microcytic and macrocytic cells). High RDW can also be seen in bone marrow disorders and after blood transfusions. Symptoms may include fatigue, weakness, pallor, and shortness of breath. Identifying and treating the underlying cause is essential for managing elevated RDW levels.
Also known as: Red Cell Distribution Width, rdw