Red blood cells contain a large amount of hemoglobin (Hb), and the functions of red blood cells are mainly completed by hemoglobin. In addition to functioning as a blood buffer substance, hemoglobin's main function is to carry oxygen (O2) and carbon dioxide (CO2).

Physiologically increased: Residents living in plateau areas tend to have higher red blood cells and hemoglobin than residents in plain areas. Drinking too little water or sweating too much, eliminating too much water can lead to temporary hemoconcentration. Causes a slight increase in red blood cells and hemoglobin. In newborns, the increase is physiological.

Pathological increase: severe vomiting, diarrhea, profuse sweating, patients with large area burns, diabetes insipidus, hyperthyroidism Crisis, diabetic acidosis, etc., due to excessive loss of water in the plasma, resulting in hemoconcentration, there will be a significant increase in the amount of red blood cells and hemoglobin. Chronic heart disease, pulmonary heart disease, cyanotic congenital heart disease, etc. due to tissue hypoxia and increase in erythropoietin in the blood, the amount of red blood cells and hemoglobin in the blood increases compensatoryly. Some tumors, such as kidney Cancer, hepatocellular carcinoma, uterine fibroids, ovarian cancer, renal embryonic carcinoma, etc. can also cause a non-compensatory increase in erythropoietin, leading to the above results. Polycythemia vera is an unknown cause of increased red blood cells. Lord's Blood Disease.