Blood Health Data Verified

High Hemoglobin Levels: Is It Dangerous?

Written by
Dr. Kamal Kant Sahu
and medically reviewed by iCliniq medical review team.

Published on May 11, 2018 and last reviewed on Feb 20, 2023   -  2 min read


High hemoglobin levels or polycythemia can be due to smoking, dehydration, or heart problems. This article describes the types and treatment options for polycythemia.

High Hemoglobin Levels: Is It Dangerous?

When Is the Hemoglobin Level Considered to Be High?

According to the conventional definition, it is considered as high hemoglobin when levels are more than 18.5 g/dL for men and 16.5 g/dL for women. High hemoglobin levels are associated with high hematocrit (also called as PCV) levels which are defined as greater than 50 % in men and greater than 45 % in women.

Polycythemia is the medical term for high hemoglobin. Polycythemia can be secondary or primary.

Primary polycythemia also called as polycythemia vera is a type of myeloproliferative disorders (the general term is blood cancer).

Secondary polycythemia is due to multifactorial reasons, few are as follows:

  1. Lung problems like asthma.
  2. Heart problems.
  3. Smoking.
  4. Dehydration.
  5. Living in high altitudes.
  6. Obesity.
  7. Stress.

So, with a good history, most cases can be grossly categorized into primary or secondary.

How to Differentiate Between Primary and Secondary?

  1. With the patient's medical history as mentioned above.
  2. Blood investigations like EPO (erythropoietin) levels, ABG (arterial blood gas analysis), specialized investigations like JAK-2 mutation analysis and bone marrow examination.



Polycythemia vera can be treated with a variety of modalities like phlebotomy (blood letting), low dose Aspirin, Hydroxyurea and in certain advanced cases Ruxolitinib.

In secondary cases, treatment is by addressing the underlying cause such as management of asthma, obesity, cessation of smoking, and other lifestyle changes.

As a final word of caution, I would like to say that not every case of high hemoglobin is blood cancer and not to get carried away or panic immediately. Please consult your general physician, and with proper history-taking, he will be able to guide you about what disease you are suffering from.

For more information consult a hematologist online -->

Last reviewed at:
20 Feb 2023  -  2 min read



Dr. Kamal Kant Sahu


Comprehensive Medical Second Opinion.Submit your Case

Related Questions & Answers

Does A Hematocrit Of 49.2 Indicate Polycythemia?

Query: Hello doctor,My Hb is 15.8 but HCT is 49.2 and total RBC count is 5.63. What is the reason? I fear about polycythemia. Is it possible to reduce HCT?  Read Full »

Can fasting lead to high RBC count?

Query: Hello doctor, I had a blood test done two months back and my RBC was 6.0, hemoglobin 17.2, and hematocrit 51, which were all high especially RBC. The blood test was in the morning and I had not eaten or drunk for eight hours before. I am an 18-year-old 130 lb male, and I was wondering if the blood ...  Read Full »

Why am I having high RBC and hemoglobin counts with low glycated hemoglobin?

Query: Hello doctor, I am 53 years old, 183 lbs, 5'4". For years, I ran a high white blood count and the oncologist said nothing can be done about that. We need to now watch red blood count and RBC distribution and watch my spleen. Now approximately nine years later, for the last four years, I am seeing r...  Read Full »

Popular Articles Most Popular Articles

Do you have a question on Polycythemia or High Hemoglobin?

Ask a Doctor Online

* guaranteed answer within 4 hours.

Disclaimer: No content published on this website is intended to be a substitute for professional medical diagnosis, advice or treatment by a trained physician. Seek advice from your physician or other qualified healthcare providers with questions you may have regarding your symptoms and medical condition for a complete medical diagnosis. Do not delay or disregard seeking professional medical advice because of something you have read on this website. Read our Editorial Process to know how we create content for health articles and queries.