What is a high hemoglobin count?

Hemoglobin is a protein in red blood cells that helps blood carry oxygen throughout the body. (Hemoglobin contains iron, which gives blood its red color.) The hemoglobin count is an indirect measurement of the number of red blood cells in your body. When the hemoglobin count is higher than normal, it may be a sign of a health problem.

Normal hemoglobin counts are 14 to 17 gm/dL (grams per deciliter) for men and 12 to 15 gm/dL for women. Hemoglobin levels depend on many factors, including age, race, gender and the general health of the person.

Hemoglobin is usually measured as part of a complete blood count (a routine blood test), along with hematocrit (the percentage of the blood that is made up of red blood cells), to help diagnose medical conditions and learn more about the person’s health.

What can cause a high hemoglobin count?

Many factors can affect the hemoglobin level. Sometimes a high hemoglobin count is the result of lifestyle or a side effect of taking medication.

Medical conditions that can cause high hemoglobin levels include:

  • Polycythemia vera (the bone marrow produces too many red blood cells)
  • Lung diseases such as COPD, emphysema or pulmonary fibrosis (lung tissue becomes scarred)
  • Heart disease, especially congenital heart disease (the baby is born with it)
  • Kidney tumors
  • Dehydration (from diarrhea or lack of fluids)
  • Hypoxia (low blood oxygen levels)
  • Carbon monoxide exposure (usually related to smoking)

Lifestyle factors that can cause a high hemoglobin count include:

  • Smoking cigarettes
  • Living at a high altitude
  • Taking performance-enhancing drugs such as anabolic steroids (for example, synthetic testosterone) or erythropoietin

Last reviewed by a Cleveland Clinic medical professional on 05/02/2018.


  • National Heart, Lung, and Blood Institute. Blood tests. Accessed 5/7/2018.
  • American Association for Clinical Chemistry/Lab Tests Online. Hemoglobin. Accessed 5/7/2018.
  • Leukemia & Lymphoma Society. Understanding Blood Counts. Accessed 5/7/2018.

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