The Role of The Spleen in Production of Blood

While the spleen does not actually produce blood, it does have important functions related to blood.

Filters Blood

The main function of the spleen is to filter your blood. As blood flows through the spleen, it checks for old, deformed or damaged red blood cells and removes them. These unhealthy red blood cells are then broken down by large white blood cells called macrophages.

Saves Useful Blood Components

As the unhealthy red blood cells are broken down, the spleen saves any useful components, such as iron. The iron, in the form of ferritin or bilirubin, eventually returns to the bone marrow and is used to make an important blood protein called hemoglobin. Hemoglobin is the part of your blood that moves oxygen from your lungs to all the other parts of your body.

Stores Blood

The blood vessels in the spleen can expand and store up to one cup of blood. Then if you bleed and need some extra blood, the spleen releases the reserve blood into your bloodstream.

Supports Immune System

The spleen is also an important part of your immune system, helping remove disease-causing microorganisms from your blood.


Even though the spleen performs important functions, you can live without it. Other parts of your body, such as lymph nodes and liver, can take over many of the functions of the spleen. However, not having a spleen does make you more vulnerable to infections.

While the spleen does not actually produce blood