Blood test

High hemoglobin level in the blood

Blood test
High hemoglobin level in the blood
Last update: 09/12/2020

What is high hemoglobin level in the blood called?

  • Hemoglobinemia

What is the normal hemoglobin level in the blood?

If you need to know which are the hemoglobin reference ranges or you require more information about the role of hemoglobin in the blood you can visit: Normal hemoglobin level in the blood

What does high hemoglobin level in the blood mean?

Hemoglobin is the protein present in the RBC (Red Blood Cells) that carries oxygen to the tissues of the body. It is usually measured in g/dl. A high hemoglobin level may be due to:

  • A high production of RBC, for example, in polycythemia vera, that it is the first possibility that should be studied.
  • A decrease in the plasma volume. This fact increases the hemoglobin concentration per volume. It may be seen in case of dehydration.

Secondary causes for hemoglobinemia includes hypoxia, inappropriate erythropoietin increase, associated with androgens or associated with chronic chemical exposure (nitrites, sulfonamides, cobalt, etc.)

Hemoglobin values are usually given in g/dl but sometimes you can see these values in mmol/l following the International System of Units (SI). In case your values are in mmol/l you can convert them using this tool:


Hemoglobinemia or a high hemoglobin level in the blood means:

  • Mild hemoglobinuria (16 - 18 g/dl in adult women and 18 - 20 g/dl in adult men):

    The hemoglobin level in the blood is a bit high, above the normal range.

    It is not a matter to be worried because it may be only due to high altitude, tobacco, obesity or stress.

  • Moderate hemoglobinuria (18 - 20 g/dl in adult women and 20 - 22 g/dl in adult men):

    Moderate hemoglobinuria is a marked polyglobulia that it is usually followed by a high hematocrit percentage (above 50% in women and 55% in men).

    It may due to a disease known as polycythemia vera.

  • Severe hemoglobinuria (> 20 g/dl in adult women and > 22 g/dl in adult men):

    Severe hemoglobinuria leads to clogging of the capillaries as a result of hemoconcentration and the risk to suffer a cardiovascular disorder increases (heart attack, stroke or angina pectoris). It is necessary to look for immediate medical attention.

    Severe hemoglobinuria may be due to a severe polycythemia vera or a dehydration consequence of a severe burn for example.

Which factors can raise the hemoglobin level in the blood?

There are some health circumstances or drugs than can raise your hemoglobin level in the blood:

  • Dehydration (due to excessive sweating, vomiting or diarrhea)
  • High altitude
  • Stress
  • Obesity
  • Burns
  • Tobacco
  • Drugs
    • Androgen
    • Antibiotics
      • Gentamicin
    • Erythropoietin (EPO)

Which diseases can raise your hemoglobin level in the blood?

There are different diseases why the hemoglobin level in the blood can be higher than normal:

  • Polycythemia vera
  • Chronic obstructive pulmonary disease
  • Sleep apnea
  • Congenital heart disease
  • Asthma
  • Hydronephrosis
  • Kidney cancer

What can I do to lower the hemoglobin level in the blood?

If your hemoglobin level in the blood is a bit high, you should consider the following tips:

  • Give up smoking
  • Follow a healthy diet to avoid obesity
  • An adequate intake of water and liquids
  • Relieve stress and anxiety

Where can I find more information about hemoglobin level in the blood?

You can visit our pages about:

Which values are considered a high hemoglobin level in the blood?

The following values are considered to be above the normal range:

IMPORTANT: These levels are expressed in gr/dl. They are an example of a healthy woman of about 45 years old with no known disease and not taking any medication. The ranges can be different depending on the laboratory or on your personal circumstances.

Mild hemoglobinemia
16.1 g/dl16.2 g/dl16.3 g/dl16.4 g/dl16.5 g/dl16.6 g/dl16.7 g/dl16.8 g/dl
16.9 g/dl17 g/dl17.1 g/dl17.2 g/dl17.3 g/dl17.4 g/dl17.5 g/dl17.6 g/dl
17.7 g/dl17.8 g/dl17.9 g/dl18 g/dl    
Moderate hemoglobinemia
18.1 g/dl18.2 g/dl18.3 g/dl18.4 g/dl18.5 g/dl18.6 g/dl18.7 g/dl18.8 g/dl
18.9 g/dl19 g/dl19.1 g/dl19.2 g/dl19.3 g/dl19.4 g/dl19.5 g/dl19.6 g/dl
19.7 g/dl19.8 g/dl19.9 g/dl20 g/dl    
Severe hemoglobinemia
20.1 g/dl20.2 g/dl20.3 g/dl20.4 g/dl20.5 g/dl20.6 g/dl20.7 g/dl20.8 g/dl
20.9 g/dl21 g/dl21.1 g/dl21.2 g/dl21.3 g/dl21.4 g/dl21.5 g/dl21.6 g/dl
21.7 g/dl21.8 g/dl21.9 g/dl22 g/dl22.1 g/dl22.2 g/dl22.3 g/dl22.4 g/dl
22.5 g/dl22.6 g/dl22.7 g/dl22.8 g/dl22.9 g/dl23 g/dl  
Medically reviewed by our Medical staff on 09/12/2020


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