There are generally three factors that contribute to high erythrocytes, one primary, another secondary, and a relative factor.
Primary factors are true erythrocytosis, a clonal chronic myeloproliferative disorder of hematopoietic stem cells. Secondary factors, on the other hand, are due to tissue hypoxia. For example, they are caused by chronic hypoxic states or lung diseases such as emphysema and pulmonary heart disease. And relative factors are mostly due to reduced blood volume due to large burns or acute dehydration, etc., resulting in high red blood cell count.
In addition, patients who are in a non-hypoxic state with increased erythrocytes are considered to be caused by an abnormal increase in erythrocytes, such as enhanced bone marrow production of erythrocytes that the body does not metabolize, and this condition is considered to be caused by tumors or kidney disease, such as gastric cancer, hepatocellular carcinoma, nephroblastoma, renal embryonal histoma, polycystic kidney, renal artery stenosis, etc.
In addition, if the red blood cells are only slightly high, and other indicators are normal, and there are no uncomfortable symptoms, it may be caused by drinking too little water and sweating a lot due to strenuous activities.