What is hemoglobin?

Written by

Lauren Dobischok
29 March, 2022

Medically checked article All HOMED-IQ content is reviewed by medical specialists

Hemoglobin (Hb) is part of the red blood cells in our body. It is important to maintain a healthy hemoglobin level to feel our best and ensure our body can function properly. When our hemoglobin value is too high or too low, physical complaints can arise.

What is hemoglobin?

Hemoglobin is a protein that allows for the absorption and transport of oxygen and carbon dioxide in red blood cells. The red blood cells in our body ensure the delivery of oxygen from the lungs to our body’s cells. Oxygen allows your muscles and organs to obtain energy from the food you eat, also known as cellular respiration. After the oxygen is released to the cells, hemoglobin is then able to absorb carbon dioxide which ends up in the lungs. The carbon dioxide then leaves the body through exhalation (Sanquin).

Why is hemoglobin important?

Hemoglobin is important because it carries oxygen from the lungs to the tissues of the body and removes carbon dioxide. This is an essential process that occurs every moment of the day. Adequate hemoglobin levels contribute to optimal functioning of your body cells and ensures the removal of waste products.

What is an optimal hemoglobin value?

The reference values for hemoglobin are as follows: (Dutch Association of Hematology):

  • Men: 8.5 – 11 mmol/l
  • Women: 7.5 – 10 mmol/l
  • Children > 6 years: 6.5 – 10 mmol/l
  • Children 1 month – 6 years: 6 – 9 mmol/l

Can your hemoglobin be too high or too low?

Yes- if your hemoglobin level is too low, you may have anemia. This means you don’t have enough healthy red blood cells to carry adequate oxygen to your body’s cells. There are various causes for this, such as kidney failure, a stomach ulcer, chemotherapy, or nutritional and vitamin deficiencies.

If your hemoglobin level is too high, your blood does transport enough oxygen, but there is an increased risk of clots. These clots can form because the blood is more viscous, which can lead to narrowing or blockage of arteries (Isala Zwolle, 2021).

What are the causes of a low hemoglobin level?

Anemia occurs when there is too little hemoglobin in the blood. This can be caused by several factors ( Máxima MC, 2022 ):

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What happens if your hemoglobin is too low?

If the hemoglobin level is too low, you have anemia. This can cause the following symptoms:

  • Fatigue
  • Pale skin
  • Heart palpitations
  • Headache
  • Hair loss
  • Shortness of breath
  • Headache
  • Cold feet and hands
  • Chest pain

How do I increase my hemoglobin level?

When you have low hemoglobin, it is important to consume more iron. There is iron in all kinds of foods, such as meat, fish, chicken, legumes, and vegetables such as spinach. It is also possible to use an iron supplement. It is advisable to check your hemoglobin level a few months after making dietary changes to see if any improvements have been made. Contact your GP if you require more advice on how to increase your hemoglobin level.


Bloedarmoede – Máxima MC. (2017, September 27). Interne Geneeskunde.

Isala. (2021, November). Hematologische aandoening (PID): H2 Optionele bijlage Myeloproliferatieve aandoeningen.

Nederlandse Internisten Vereniging. (2020, January 30). Normaalwaarden ».

Wat is hemoglobine en welke waarde is normaal? | Sanquin. (n.d.).

About the author

Lauren Dobischok

Lauren is a health scientist and science communicator currently living in the Netherlands. Originally from Canada, she completed a Research Master’s in Health Sciences at the Netherlands Institute of Health Sciences at Erasmus University Rotterdam (NIHES) with a specialisation in epidemiology. Prior to her master’s degree, she completed a Bachelor’s degree in Health Sciences at Simon Fraser University. With a background in public health, her goal is to create accurate scientific content that is easy to understand and empowers people to make informed decisions. Within Homed-IQ, Lauren works as a Product Developer and Content Lead, working closely with physicians and scientists on medical devices for Homed-IQ’s new products and written communications.