Erythrocyte Count

The erythrocyte count, also known as a red blood cell (RBC) count, is a laboratory test that measures the number of red blood cells in a sample of blood.

Purpose

The purpose of an erythrocyte count is to:

• Diagnose and monitor conditions that affect red blood cell production, such as anemia, polycythemia, and bone marrow disorders.
• Evaluate the effectiveness of treatments for these conditions.
• Monitor patients with chronic diseases, such as kidney disease or cancer, that can affect red blood cell production.

Procedure

To perform an erythrocyte count, a healthcare professional will:

• Collect a sample of blood from a vein in the arm or from a fingerstick.
• Place the blood sample into a tube that contains an anticoagulant to prevent clotting.
• Send the blood sample to a laboratory for analysis.

Analysis

In the laboratory, the erythrocyte count is typically performed using an automated hematology analyzer, which uses electrical impedance or laser technology to count the number of red blood cells in the sample.

Reference Ranges

The reference ranges for erythrocyte counts vary depending on age, sex, and other factors. Typical reference ranges are:

• Adult men: 4.32-5.72 million cells per microliter (µL)
• Adult women: 3.90-5.03 million cells per microliter (µL)
• Children and infants: vary depending on age

Abnormal Results

An abnormal erythrocyte count can indicate a range of conditions, including:

• Anemia (low RBC count)
• Polycythemia (high RBC count)
• Bone marrow disorders, such as leukemia or lymphoma
• Kidney disease or cancer

Clinical Significance

The erythrocyte count is an important diagnostic tool that can help healthcare professionals diagnose and monitor a range of conditions. It is often used in conjunction with other laboratory tests, such as the white blood cell count and platelet count, to provide a comprehensive picture of a patient's hematological status.