High Hemoglobin Count

What It Means and How It’s Treated

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A high hemoglobin level means you have an above-normal amount of the protein in red blood cells that delivers oxygen throughout your body and brings carbon dioxide back to the lungs. When the body needs more oxygen than it is getting, hemoglobin levels rise to fix that.

High hemoglobin is often caught during routine blood tests. It may be due to lifestyle factors, like smoking or living in a high altitude, or medical conditions that promote low blood oxygen, like heart failure. Diseases that increase red blood cell production can also be to blame.

This article looks at the symptoms and causes of high hemoglobin levels, how it's diagnosed and treated, and what lifestyle changes might help keep your levels in the normal range.

High hemoglobin is detected with a blood test

SolStock / Getty Images

Symptoms of High Hemoglobin

High hemoglobin levels themselves usually don't cause any symptoms. Sometimes, they may cause:

  • Headaches
  • Dizziness
  • Symptoms of the condition causing high hemoglobin

The symptoms of the underlying cause of high hemoglobin can, of course, vary.

Complications of high hemoglobin can be serious. They include:

Causes of High Hemoglobin

Several lifestyle issues and medical conditions can cause high hemoglobin levels.

Many conditions that lead to high hemoglobin are chronic. It's possible that you may be diagnosed before getting an abnormal hemoglobin test result.

Lifestyle Issues

Lifestyle causes of elevated hemoglobin levels include: 

  • Smoking: Red blood cells and hemoglobin increase to compensate for high levels of carbon monoxide in cigarette smoke.
  • High altitude: Lower oxygen pressure in your environment makes your body require more hemoglobin to maintain your oxygen needs.

Sometimes, dehydration can give you false high hemoglobin results when levels are normal. This is believed to be because dehydration changes the amount of fluid in your blood. Rehydrating usually corrects the measurement. 

Medical Conditions

These conditions can make your body produce excess red blood cells, and high hemoglobin is a consequence of that: 

Diagnosing High Hemoglobin

High hemoglobin levels show up in a blood test that's part of a routine complete blood cell count (CBC).

You'll be sent for a simple blood draw, where a healthcare professional will collect blood in a syringe and send it to a laboratory for testing.

Normal hemoglobin values vary slightly depending on the lab. Hemoglobin is usually reported in grams per deciliter (g/dL).

Assigned Sex Normal Hemoglobin
Male 13.5 to 17.5 g/dL 
Female 12.0 to 15.5 g/dL

Treatment of High Hemoglobin

The treatment for a high hemoglobin level depends on the cause. You may just need treatment for the underlying condition, or you may need additional treatment for the high hemoglobin.

High hemoglobin, especially in polycythemia vera, is often treated with therapeutic phlebotomy. That involves removing a unit of blood (similar to making a blood donation). This may need to be done several times.

High hemoglobin is also treated with medication to reduce the number of red blood cells, which can decrease the effects and complications of the condition.

Diet and Lifestyle Changes

If you have high hemoglobin, it’s important that you maintain a healthy diet. No specific dietary recommendations have been established, the following are good guidelines to follow:

  • Stay hydrated
  • Avoid alcohol
  • Avoid foods that are high in sugar or fat
  • Eat an ample amount of fruit, vegetables, and lean protein


Elevated hemoglobin doesn’t usually cause symptoms, but it can cause complications, including blood clots. A high hemoglobin level is often an indicator of disease, including polycythemia vera, cancer, heart disease, lung disease, and kidney or liver disease.

Smoking and high altitudes can also cause hemoglobin levels to increase.

Hemoglobin levels can be checked with a routine blood test. Treatment is usually necessary for the underlying cause, and sometimes treatment is specifically needed for high hemoglobin levels as well.

Frequently Asked Questions

  • What can I do if my hemoglobin is high?

    If you smoke, stop. And make sure you stay hydrated and eat a healthful diet. And be sure to follow up with your healthcare provider and get any additional tests they suggest. Once the cause of your high hemoglobin is determined, proper treatment can be prescribed.

  • Are there any medications that can cause high hemoglobin?

    Erythropoietin is a medication that can be used to raise red blood cells if they are low. Misuse can cause high hemoglobin levels.

  • Does dehydration cause high hemoglobin?

    No, but dehydration can give you a false high hemoglobin reading on a blood test. This is because it lowers the fluid volume in your blood relative to red blood cells, which contain hemoglobin.

  • What could happen if my hemoglobin level gets too high?

    Having a high red blood cell concentration could increase your risk of blood clots. If your hemoglobin is high due to chronic illness such as cancer or kidney disease, that disease may continue to progress and cause health problems until it is treated.

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Heidi Moawad, MD
Heidi Moawad is a neurologist and expert in the field of brain health and neurological disorders. Dr. Moawad regularly writes and edits health and career content for medical books and publications.