17 year old. had cbc: red blood cells: 5.8, hemaglobin-17.3 & hematocrit-52.0%. previous cbcs show its been elevating over last 3 yrs. polycyhtemia?

Seek cause: There are many causes for polycythemia. These are high-end for a young man, but you want to rule out everything from a hemoglobin variant to a right-to-left cardiac shunt to an erythropoietin-making tumor to sleep apnea to your taking Anabolic steroids without knowing it (this can happen in today's world of gym-produced fitness beverages.).

Normal: To have polycythemia, a man has to have a hemoglobin greater than 18.5 based on the world health organization (who) guidelines. You are young and healthy, it is normal. One thing, of you smoke, this could be a cause. Hope this helps.