A high hemoglobin value of 166g/L is generally not very serious, and the common causes include physiological high hemoglobin, water-deficiency diseases, hypoxia diseases, tumors, and true erythrocytosis. 1. Physiological high hemoglobin: For example, people living in highland areas, newborn babies, drinking too little water or sweating too much, all of them may have physiological high hemoglobin. 2. Water-deficiency diseases: burns, uremia, severe vomiting or severe diarrhea may cause water loss in the blood, resulting in an increase in hemoglobin. 3. Hypoxic diseases: Diseases such as pulmonary heart disease and chronic obstructive pulmonary disease can cause tissue hypoxia, leading to an increase in hemoglobin. 4. Tumors: Liver cancer and other tumors may also cause elevated hemoglobin. 5. True erythrocytosis: high hemoglobin can occur, and the prognosis is generally better after active treatment (hydroxyurea). High hemoglobin may also be caused by other reasons, once the situation of high hemoglobin should go to the hospital in time to find out the cause of high hemoglobin and carry out targeted treatment under the guidance of physicians.