High Hemoglobin Count: What It Means and How It’s Treated

It's not as common as low hemoglobin

Hemoglobin is a protein that is found in red blood cells. This protein binds to oxygen and carbon dioxide, which allows red blood cells to carry these molecules as they flow in the blood vessels throughout the body. 

Your hemoglobin level can be measured with a blood test. You may be familiar with low levels of hemoglobin as the definition of anemia, but high levels aren't discussed as often; read on to learn more.

High hemoglobin is detected with a blood test

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Hemoglobin (Hgb) Blood Test

Your hemoglobin can be measured in a sample of your blood. This is part of a routine complete blood cell count (CBC)

If your doctor orders this test for you, there is nothing you need to do to prepare.

During the test:

  • A healthcare professional will find a vein before your blood is collected, usually on your hand or arm.
  • They will clean the area of skin with an alcohol pad and place a band around your arm.
  • Then they will insert a needle to collect the blood. The needle should remain in your vein for a minute or less.
  • The healthcare professional will remove the needle and place a bandage over the puncture site. You may be asked to place your finger over the area and apply pressure for a few minutes.
  • You should keep the bandage on for a few hours to ensure bleeding has stopped.

If you are having other blood tests at the same time that require special preparation, you might be asked to prepare by adjusting medications or fasting from food for a few hours before your test. 

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

Normal hemoglobin values
Males 13.5 to 17.5 g/dL 
Females 12.0 to 15.5 g/dL

High Hemoglobin Levels

When hemoglobin is high, it can be a sign of certain medical conditions. Hemoglobin levels will be elevated if you have too many red blood cells or if your body makes too much hemoglobin. 

Your body can make more than the normal amount of hemoglobin as a way to compensate for low oxygen levels. Also, some diseases result in excess red blood cell production, which causes hemoglobin levels to be elevated.

Signs and Symptoms

Usually, elevated hemoglobin levels do not cause any symptoms. Sometimes, having a high hemoglobin level can cause headaches or dizziness. You are likely to have symptoms of the underlying condition that is causing you to have a high hemoglobin level. These symptoms can vary with different underlying causes.

Causes and Risk Factors

Several medical issues can cause high hemoglobin levels. Many conditions that lead to high hemoglobin are chronic diseases, so you and your doctor might already know that you have the underlying cause before it affects your hemoglobin.

Sometimes dehydration can make your hemoglobin level seem high when measured with a blood test, even when you don’t have a high total amount of hemoglobin. Regaining normal hydration will usually correct your hemoglobin measurement if it is rechecked. 

Lifestyle causes of elevated hemoglobin levels include: 

  • Smoking: High hemoglobin levels are very common in smokers. 
  • High altitude: When you are in a high elevation, the lower oxygen pressure in your environment makes your body require more hemoglobin to maintain your oxygen needs.
  • Erythropoietin: This natural kidney hormone stimulates red blood cell production. Some people need to take this hormone to compensate for a medical condition. It is also misused in some situations that involve physical or athletic performance.

Medical conditions that cause high hemoglobin include: 

These conditions can cause your body to make more red blood cells, and hemoglobin is a component of red blood cells.

Medical Treatment

The treatment for a high hemoglobin level depends on the cause. For example, if you have cancer, respiratory disease, heart disease, or kidney disease, your medical condition would be treated. You may also need separate treatment for your elevated hemoglobin level.

Polycythemia vera is often treated with therapeutic phlebotomy, in which a unit of blood is removed (similar to making a blood donation). Sometimes it is 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. There are no specific dietary recommendations that lower hemoglobin.

General guidelines include: 

  • Stay well 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. It can occur with polycythemia vera, cancer, heart disease, lung disease, and kidney or liver disease.

Smoking and high altitudes can also cause hemoglobin levels to increase. Treatment is usually necessary for the underlying cause, and sometimes treatment is specifically needed for high hemoglobin levels as well.

A Word From Verywell

Hemoglobin can be measured with a blood test. While low hemoglobin is a more common concern than high hemoglobin, sometimes high hemoglobin can occur. If you have any abnormalities on your blood tests, make sure you follow up with your healthcare professional so you can get a diagnosis and treatment for the underlying condition.

Frequently Asked Questions

  • What can I do if my hemoglobin is high?

    Usually, your doctor’s office will call you if your hemoglobin level is found to be high based on a blood test. The next step depends on your overall health and medical risk factors. You might need to have your hemoglobin test repeated, as well as other tests to identify causes of high hemoglobin levels.

    If you have a known cause related to lifestyle factors, such as smoking or spending time in a high-altitude location, your doctor may advise you to stop smoking and stay hydrated to maintain better health.

  • 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, and it can also cause hemoglobin to be too high if it is misused.

  • Does dehydration cause high hemoglobin?

    Dehydration can make you have a high hemoglobin level on a blood test because it causes you to have a low fluid blood volume compared to your number of red blood cells, but it does not make the number of red blood cells increase.

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

    It depends on the cause. If you have a high red blood cell concentration, then you could be at a higher-than-normal risk of blood clots. If your hemoglobin count is high due to a chronic illness such as cancer or kidney disease, your underlying illness can continue to progress and cause health problems until it is treated.

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4 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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