What is bone marrow and what is its primary function in the body?

Bone marrow is spongy tissue located inside certain bones, such as the hip and thigh bones. It serves as the body’s factory for stem cells—unspecialized cells with the ability to develop into various types of blood cells that the body needs to perform vital functions. These stem cells can differentiate into red blood cells, white blood cells, and platelets, each playing a vital and specific role in maintaining the body's health [1].

Types of blood cells produced by bone marrow and their functions

• Red blood cells: These cells are known for their ability to carry oxygen from the lungs to all parts of the body and are essential for tissue and organ function. A deficiency can lead to anemia [1].
• White blood cells: These are a fundamental part of the immune system, fighting off various infections and diseases. There are multiple types of white blood cells, such as granulocytes and lymphocytes, each with a specific role in defending the body [1].
• Platelets: These play a crucial role in the blood clotting process and stopping bleeding in the event of an injury. Any abnormality in their number or function can lead to bleeding or clotting problems [1].

The importance of bone marrow in maintaining health

Bone marrow constantly works to replenish the body's supply of blood cells, ensuring that you have enough red cells to carry oxygen, white cells to fight infection, and platelets to stop bleeding. When bone marrow becomes diseased, its ability to produce these cells correctly may be affected, leading to a wide range of health problems [1].

For example, in conditions such as leukemia, the bone marrow produces abnormal white blood cells. In aplastic anemia, the bone marrow does not produce enough red blood cells. Meanwhile, in myeloproliferative disorders, the bone marrow may produce too many white blood cells [1]. Other diseases, such as lymphoma, can spread to the bone marrow and affect blood cell production [1].

When to consult a doctor?

If you are experiencing persistent symptoms such as severe fatigue, unexplained fever, unexplained weight loss, easy bleeding or bruising, or bone pain, these may be signs of a bone marrow problem. It is important to consult a doctor to undergo the necessary examinations, such as blood tests and bone marrow tests, to determine the cause and obtain the appropriate diagnosis and treatment [3]. Some bone marrow diseases can progress to rapidly growing types of blood cancer, such as acute myeloid leukemia, underscoring the importance of early diagnosis [2].

For more information on bone marrow diseases and how they affect blood cell production, you can visit Bone marrow diseases: Blood cell production (Arabic).

Medical references

• Bone Marrow Diseases
• Myelodysplastic/ Myeloproliferative Neoplasms Treatment (PDQ®)–Patient Version
• 8p11 myeloproliferative syndrome: MedlinePlus Genetics