A high hemoglobin count indicates an above-normal level of the iron-containing protein in red blood cells. Hemoglobin (often abbreviated as Hb or Hgb) is the oxygen-carrying component of red blood cells.
Hemoglobin, which gives red blood cells their color, helps carry oxygen from the lungs to the rest of the body and carbon dioxide back to the lungs to be exhaled.
The threshold for a high hemoglobin count differs slightly from one medical practice to another. It's generally defined as more than 17.5 grams (g) of hemoglobin per deciliter (dL) of blood for men and 15.5 g/dL for women. In children, the definition of a high hemoglobin count varies with age and sex. Hemoglobin count may also vary due to time of day, how well-hydrated you are and altitude.
A high hemoglobin count occurs most commonly when your body requires an increased oxygen-carrying capacity, usually because:
High hemoglobin count occurs less commonly because:
If you have a high hemoglobin count without other abnormalities, it's unlikely to indicate a related serious condition. Conditions that can cause a high hemoglobin count include:
A high hemoglobin count is usually found from tests your doctor has ordered to diagnose another condition. Your doctor is likely to order other tests to help determine the cause of your high hemoglobin count.