Definition of high hemoglobin count
A high hemoglobin count indicates an above-average concentration of the oxygen-carrying protein hemoglobin in your blood. Hemoglobin (Hg or Hgb) is the main component of red blood cells. Hemoglobin count – also referred to as hemoglobin level – indicates your blood’s oxygen-carrying capacity.
A high hemoglobin count is somewhat different from a high red blood cell count, because each cell may not have the same amount of hemoglobin proteins. Therefore, you could have a high hemoglobin count even if your red blood cell count falls within the normal range.
The threshold for a high hemoglobin count is slightly different 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.
Causes of high hemoglobin count
High hemoglobin count may occur because:
- Your red blood cell production increases to compensate for chronically low blood oxygen levels due to poor heart or lung function.
- You have a bone marrow dysfunction that results in increased production of red blood cells.
- Your red blood cell production increases to compensate for a limited oxygen supply in higher altitudes.
- You smoke.
- You’ve taken drugs or hormones, most commonly erythropoietin (EPO), that stimulate red blood cell production. You’re not likely to get a high hemoglobin count from EPO given to you if you have chronic kidney disease. However, EPO doping — getting injections to enhance athletic performance — can cause a high hemoglobin count.
Specific disorders or other factors that may cause high hemoglobin count include:
- COPD — Chronic obstructive pulmonary disease
- Heart failure
- Kidney cancer
- Liver cancer
- Living at a high altitude, where there’s less oxygen in the air
- Other types of heart disease
- Other types of lung disease
- Polycythemia vera
- Smoking, which may result in low blood oxygen levels
When to see a doctor
A high hemoglobin count is rarely an unexpected finding or simply discovered by chance. It’s usually found when your doctor has ordered tests to help diagnose a condition you’re already experiencing. Talk to your doctor about what these results mean. A high hemoglobin count and results from other tests may already indicate the cause of your illness, or your doctor may suggest other tests to check your condition.