Red blood cell count

Red blood cell count

Red blood cells under a microscope
Latin	Numerus erythrocytorum
System	Hematopoietic system
Location	Bloodstream

The red blood cell count, also known as the numerus erythrocytorum, refers to the number of red blood cells (RBCs) present in a given volume of blood. It is an important parameter used in medical diagnostics to assess the overall health and functioning of the hematopoietic system.

Physiology

Red blood cells, also called erythrocytes, are the most abundant cells in the bloodstream. They are responsible for transporting oxygen from the lungs to various tissues and organs throughout the body. The red color of these cells is due to the presence of a protein called hemoglobin, which binds to oxygen and carries it to the cells.

The red blood cell count is typically measured in units of cells per microliter (μL) of blood. In healthy adults, the normal range for red blood cell count is approximately 4.5 to 5.5 million cells/μL for males and 4.0 to 5.0 million cells/μL for females. These values may vary slightly depending on the laboratory and the individual's age, sex, and overall health.

Clinical significance

Abnormalities in red blood cell count can indicate various medical conditions. A low red blood cell count, known as anemia, may be caused by factors such as nutritional deficiencies, chronic diseases, bone marrow disorders, or excessive bleeding. Anemia can lead to symptoms such as fatigue, weakness, shortness of breath, and pale skin.

On the other hand, a high red blood cell count, known as polycythemia, may be a result of conditions such as dehydration, lung diseases, kidney diseases, or bone marrow disorders. Polycythemia can lead to symptoms such as headache, dizziness, blurred vision, and increased blood clotting.

Measurement

The red blood cell count can be determined through a simple blood test called a complete blood count (CBC). During this test, a sample of blood is collected from a vein, usually in the arm, and sent to a laboratory for analysis. The blood sample is processed, and the number of red blood cells is counted using automated machines.

Factors affecting red blood cell count

Several factors can influence the red blood cell count. These include:

Hematopoietic disorders: Conditions affecting the production or destruction of red blood cells can lead to abnormal red blood cell counts. Examples include aplastic anemia, hemolytic anemia, and myelodysplastic syndromes.

Nutritional deficiencies: Deficiencies in nutrients such as iron, vitamin B12, and folate can impair the production of red blood cells, leading to a decreased red blood cell count.

Chronic diseases: Certain chronic diseases, such as kidney disease, liver disease, and autoimmune disorders, can affect the production and lifespan of red blood cells, resulting in abnormal red blood cell counts.

Medications: Some medications, such as chemotherapy drugs and certain antibiotics, can cause changes in red blood cell count as a side effect.

Altitude: Red blood cell count tends to increase at higher altitudes due to the body's adaptation to lower oxygen levels.

Treatment

The treatment for abnormal red blood cell count depends on the underlying cause. In cases of anemia, treatment may involve addressing the nutritional deficiencies, managing the underlying chronic disease, or administering blood transfusions. In cases of polycythemia, treatment may involve addressing the underlying condition, such as hydration or medication to reduce the production of red blood cells.

See also

• Hematocrit
• Hemoglobin
• Complete blood count