A high hemoglobin level usually develops without symptoms over many years, so is often discovered with routine blood tests. When signs do appear they can be vague, such as headaches, fatigue, weakness, and dizziness.
A diagnosis of high hemoglobin 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 your lungs. When the body needs more oxygen than it is getting, hemoglobin levels rise to fix that.
A high level 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.
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Symptoms of High Hemoglobin
High hemoglobin levels usually don't cause any symptoms. If symptoms are present, they may include:
- Headaches
- Fatigue
- Weakness
- Dizziness
- Blurred vision
- Ringing in the ears (tinnitus)
- Symptoms of the underlying condition causing levels to rise (which can vary)
Complications of high hemoglobin can be serious. They include:
- Heart attack
- Stroke
- Blood clots
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 given a diagnosis before getting an abnormal hemoglobin test result.
Lifestyle
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:
- Chronic low oxygen level
- Chronic obstructive pulmonary disease (COPD) (a group of chronic, inflammatory lung diseases that includes emphysema)
- Heart failure
- Kidney disease
- Liver or kidney cancer
- Polycythemia vera (a blood disorder)
- Erythropoietin (a kidney hormone that stimulates red blood cell production and is used to treat some medical conditions; it is sometimes misused to enhance athletic performance)
Abnormal Hemoglobin Level Causes
When to See a Healthcare Provider
While a random headache or dizzy spell probably isn't cause for concern, reach out to a healthcare provider if dizzy spells or headaches become more frequent or consistent, or are otherwise concerning.
It's also important to contact a healthcare provider if you experience any symptoms of an underlying condition that causes high hemoglobin.
Diagnosing High Hemoglobin
High hemoglobin levels show up in a blood test that is part of a routine complete blood cell count (CBC). This is a simple blood draw. A healthcare provider 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 |
What Causes High or Low Hemoglobin Levels?
What Can I Do if My Hemoglobin Is High?
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 withtherapeutic phlebotomy. This involves removing a unit of blood, similar to making a blood donation. It 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 Changes
If you have high hemoglobin, it’s important to maintain a healthy diet. No specific dietary recommendations have been established, but staying hydrated and avoiding alcohol is always beneficial.
It's also important to avoid foods that are high in sugar, which can contribute to obesity, inflammation, and other conditions that increase the risk of heart disease.
Limit your intake of foods containing trans fats, which are in many processed foods, and saturated fats. Foods containing saturated fat include:
- Cured meats like salami
- Sausage and bacon
- Red meat
- Cheese
- Butter
- Some baked goods
Aim to eat a healthy diet that includes:
- An ample amount of fruits and veggies
- Whole grains
- Protein sources such as fish, seafood, nuts, and lean lean, unprocessed meats or poultry
What to Eat When You Have Polycythemia Vera
Lifestyle Changes
Exercising regularly can help maintain overall health and lower your risk of developing some conditions that lead to high hemoglobin. The American Heart Association recommends aiming for at least 150 minutes of moderate exercise or 75 minutes of vigorous physical activity a week.
Getting adequate sleep is also important for optimal health. Adults ages 18 to 60 get at least seven hours of sleep a night, according to the American Academy of Sleep Medicine.
Preventing High Hemoglobin
Sometimes you can't ward off high hemoglobin. This is the case if you have a condition such as polycythemia vera, which can't be prevented.
However, depending on the cause, you may be able to improve a high hemoglobin level by:
- Not smoking or quitting
- Living at a low altitude
- Staying hydrated
Maintaining a healthy lifestyle can help prevent some conditions that cause high hemoglobin, such as heart failure and kidney disease. Healthy lifestyle choices include:
- Regularly eating fruits and veggies
- Limiting foods high in sugar, saturated fats, and transfats
- Not drinking alcohol
- Exercising regularly
Summary
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
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.
Learn MorePreventing Dehydration
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.
Learn MoreHow Blood Clots Are Treated
12 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
Dr. Moawad is a neurologist and expert in brain health. She regularly writes and edits health content for medical books and publications.
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