Why does a high red blood cell count occur?
Red blood cells in the blood are mainly responsible for transporting oxygen and nutrients. Because these cells are found to be red under a microscope, they are called red blood cells. The number of red blood cells in our bodies generally maintains a relatively stable level. If it is too high or too low, it is considered abnormal. If the number of red blood cells is high, it may be related to the living environment, the lungs, or hypoxia in the heart.
Polycythemia is characterized by a significant increase in the number of red blood cells, hemoglobin, hematocrit, and total blood volume, exceeding normal levels. In children, hemoglobin levels exceeding 180g/L (16g/dl), hematocrit levels greater than 55%, and the absolute value of red blood cell volume per kilogram of body weight exceeding 35ml, excluding relative polycythemia due to blood concentration caused by acute dehydration or burns, can be diagnosed. This condition can be divided into two major categories: primary and secondary. Primary polycythemia is also known as true polycythemia vera, while secondary polycythemia is mainly caused by tissue hypoxia.
The normal range of red blood cell count is 3.8 to 6.0 million per mm3 for males and 3.8 to 5.5 million per mm3 for females. Normal indices are 4.0-5.5 × 10^12 cells per liter for males and 3.5-5.0 × 10^12 cells per liter for females. Most of the blood is composed of red blood cells, which transport oxygen from the lungs to tissue cells throughout the body and carry carbon dioxide away. When the number of red blood cells decreases, the ability to transport oxygen decreases, leading to a hypoxic state and anemia. In severe cases, it can be life-threatening. However, if the number increases excessively, the blood becomes thicker and less mobile, making it easy for blood vessels to become blocked.
Red blood cells are very small, with approximately 5 million red blood cells per cubic millimeter of blood, and the number of red blood cells in the human body can reach up to 25 billion. The number of red blood cells can vary with external conditions and age. Residents of high altitudes and newborns can have red blood cell counts exceeding 6 million per mm3. People who engage in sports or regular exercise also tend to have higher red blood cell counts. Hemoglobin levels range from 12-15g/100ml for males and 11-13g/100ml for females.
