What Is Hemoglobin?
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Hemoglobin - Average, High and Low Values

Published on Jul 20, 2022 and last reviewed on Feb 20, 2023   -  5 min read


Hemoglobin is a protein molecule of RBC that provides oxygen to the tissues. Read the article mentioned below.

Hemoglobin - Average, High and Low Values


Hemoglobin is an iron-containing protein competent in the red blood cells that transports oxygen to the tissues and organs. In the oxygenated state, it is called oxyhemoglobin and has the color of the blood - bright red. In the reduced state, it changes to a purplish-blue color. Hemoglobin is developed in the bone marrow. When red blood cells are used, hemoglobin is broken down, and the iron is rescued. The rescued iron is then transported by proteins (transferrin) in the bone marrow and re-used to generate new red blood cells. The left-over hemoglobin forms the basis of bilirubin.

What Is Hemoglobin?

Hemoglobin (Hgb or Hb) is the protein molecule of red blood cells that supply the oxygen from the lungs to the body's tissues and extracts carbon dioxide back to the lungs. Hemoglobin indicates the body's oxygen level and the blood's iron levels. Hemoglobin is generally measured as a part of the routine complete blood count (CBC) test from a blood sample.

What Is the Normal Hemoglobin Level?

The hemoglobin level is referred to as the amount of hemoglobin in grams (gm) per deciliter (dL) of the whole blood, a deciliter being 100 milliliters. The normal range for hemoglobin is calculated based on age and the gender of the person. The normal ranges of hemoglobin are:

  • Newborns: 17 to 22 gm/dL.
  • One week: 15 to 20 gm/dL.
  • One month: 11 to 15 gm/dL.
  • Children: 11 to 13 gm/dL.
  • Adult males: 14 to 18 gm/dL.
  • Adult females: 12 to 16 gm/dL.
  • Men above middle age: 12.4 to 14.9 gm/dL.

Pregnant women are recommended to avoid both high and low hemoglobin levels as it can lead to increased risks of stillbirths, premature birth, or low birth weight babies.

When Should I Get a Hemoglobin Test?

You may get a complete blood count to measure hemoglobin if you encounter signs and symptoms of low oxygen or low iron. These symptoms could be:

Although less presented, high hemoglobin levels can also cause health problems. The CBC test may be advised if you have signs of abnormally high hemoglobin levels, such as:

  • Blurry or disturbed vision.

  • Repetitive headaches.

  • Slurred speech.

  • Redness is seen on the face due to an increase in hemoglobin, as it is red in color.

What Does a Low Hemoglobin Level Mean?

A low hemoglobin level denotes anemia or a low RBC count. Some of the common causes of anemia are:

  • Blood loss (traumatic injury, surgery).

  • Deficiency (iron, vitamin B12, folate).

  • Suppression of red blood cell synthesis by chemotherapy or kidney dysfunction.

  • Abnormal structure of hemoglobin (seen with sickle cell anemia or thalassemia).

  • Anemia is caused by red blood cells dying earlier than normal (hemolytic anemia).

  • Heavy menstrual periods.

  • Chronic kidney disease.

  • Deficient production of red blood cells in the bone marrow. This may be due to blood cancer, other drug toxicity, radiation therapy, infection, or bone marrow disorders.

  • Deficiency of iron, folate, vitamin B12, or vitamin B6.

  • Chronic illnesses, such as arthritis.

What Does a High Hemoglobin Level Mean?

Greater than normal hemoglobin levels are generally seen in people living at high altitudes and in smokers. Dehydration produces a false reading of high hemoglobin levels that vanishes when the fluid is balanced.

Some other infrequent causes of high hemoglobin levels are:

  • Chronic lung disease.

  • Certain tumors such as kidney cancer.

  • A disorder of the bone marrow known as polycythemia rubra vera in which the bone marrow produces too many red blood cells.

  • Abuse of erythropoietin by athletes for blood doping purposes (increasing the amount of oxygen available to the body by increasing the production of red blood cells).

  • Certain birth defects of the heart.

  • Dysfunction in the right side of the heart.

  • Severe chronic obstructive pulmonary disease (COPD).

  • Scarring or thickening of the lungs and other severe lung disorders.

What Is the Hemoglobin A1c Test?

Hemoglobin A1c or glycosylated hemoglobin is a vague indication of blood sugar control level in people with diabetes mellitus over three months. As a good amount of glucose (blood sugar) circulates in the blood on a daily basis, the greater the level of glucose is tied to the circulating hemoglobin. Normal hemoglobin A1c levels range approximately 35 mg/dL over 135 mg/dL. A hemoglobin A1c of six percent estimates an average blood sugar level of 135 mg/dL (milligrams per deciliters) over the previous three months.

How to Increase Your Hemoglobin Levels?

Low hemoglobin levels can occur in three circumstances such as:

  • Decrease in red blood cell production.

  • Altered bone marrow causes an increase in red blood cell destruction (seen with liver disease).

  • Blood loss from trauma (roadside accidents).

You can increase hemoglobin levels by treating the underlying problems and maintaining a healthy lifestyle. Some ways to increase the hemoglobin levels are discussed below:

  • Red blood cells transfusion (emergency procedure).
  • Starting erythropoietin (a hormone used to regenerate red blood cell production).

  • Taking iron and other nutrient supplements.

  • Intake of iron-rich foods (eggs, spinach, beans, lean meats, and seafood).

  • Foods that are rich in co-factors (such as vitamin B6, folic acid, vitamin B12, and vitamin C). Maintaining normal hemoglobin levels with foods such as fish, vegetables, nuts, cereals, peas, and citrus fruits.

You must not self-medicate for low hemoglobin levels without first discussing with your physician as side effects from these treatments and excess iron intake may cause severe side effects.


Identifying the underlying cause and treating the condition accordingly will help rectify your hemoglobin count. Keeping the hemoglobin levels in check and maintaining proper levels is essential for an individual's overall health. As this protein component of the red blood cells performs one crucial function of carrying oxygen from your lungs to your tissues, it is always safe to keep the levels tracked periodically. Most importantly, consuming a proper diet and following a proper lifestyle can help you maintain your hemoglobin at standard levels.

Last reviewed at:
20 Feb 2023  -  5 min read




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