Erythrocytes (RBC)
Erythrocytes (RBC) are red blood cells whose main function is to transport oxygen from the lungs to tissues and carry carbon dioxide back. Erythrocytes contain hemoglobin, which enables oxygen transport. These cells constitute the majority of the formed elements in blood.
Normal erythrocyte values:
- Men: 4.5–5.5 ×10¹²/L
- Women: 3.9–4.7 ×10¹²/L
- Children: 3.8–5.1 ×10¹²/L (depending on age)
- Newborns: up to 6.5 ×10¹²/L
Causes of increased erythrocytes (erythrocytosis):
- Dehydration (heat, vomiting, diarrhea, physical exertion)
- Smoking, prolonged stay at high altitudes (hypoxia)
- Chronic heart and lung diseases
- Endocrine disorders (e.g., Cushing’s disease)
- Polycythemia (primary — hematopoietic system disease)
Causes of decreased erythrocytes (erythropenia):
- Anemias (iron, B12, and folate deficiency)
- Blood loss (acute and chronic)
- Pregnancy (physiological decrease due to increased plasma volume)
- Chronic inflammation, infections
- Bone marrow diseases (aplastic anemia, leukemias)
- Hemolysis (destruction of erythrocytes)
Why erythrocyte level is measured:
- Assessment of general health and hematopoiesis function
- Diagnosis of anemia, dehydration, hypoxia
- Monitoring heart, lung, and kidney diseases
- Monitoring treatment effectiveness for anemia and other conditions
How the test is performed:
- Blood is taken from a finger or vein, preferably fasting
- Avoid physical exertion, stress, and smoking before the test
Important to know:
- Increased erythrocyte count raises blood viscosity, which may lead to thrombosis and impaired microcirculation.
- Low values are accompanied by weakness, dizziness, shortness of breath, especially during physical activity.
- Erythrocyte count is always evaluated together with hemoglobin, hematocrit, and erythrocyte indices (MCV, MCH, MCHC).