Test & Diagnostics 77

Testosterone deficiency

3 min read

Simon Körösi

Reviewed by: Gustav Grippe

What does testosterone do in the body?


Testosterone serves several important functions in the body, with the following being the most well-known:

It is the primary sex hormone/androgen in males.


Playing a crucial role in the development of the male reproductive system.

Essential for sperm production.

Important for erectile function.

Influences sex drive.


It is vital for muscle mass.


Increases muscle protein synthesis, leading to increased strength and muscle mass.


It is important for bone density.


Promoting bone formation, resulting in increased bone density.

In addition to these key functions, testosterone also has several other important roles:

It helps maintain levels of red blood cells.

stimulating erythropoietin (EPO) production and iron utilization, promoting the formation of red blood cells.


influencing the distribution of body fat.


directing weight loss predominantly towards fat, rather than fat and muscle.


preventing precursor cells from developing into mature fat cells.

What is testosterone deficiency?


Testosterone deficiency, also known as male hypogonadism, refers to lower-than-normal levels of the male sex hormone testosterone in the body, which are insufficient for the proper functioning of testosterone-dependent processes.


How is testosterone deficiency diagnosed?


The diagnosis of testosterone deficiency is established when the following criteria are met:

Low levels of testosterone in the blood


Symptoms consistent with testosterone deficiency





Hypogonadism can be divided into two types:


Primary hypogonadism - When testosterone deficiency is caused by direct testicular dysfunction, which can occur due to testicular injury or testicular cancer.


Secondary hypogonadism - When testosterone deficiency is caused by a condition affecting another organ, which in turn leads to testosterone deficiency. This occurs when the signals to the testicles to produce testosterone are not functioning properly. Examples include underfunctioning of the pituitary gland or hypothalamus.


Primary and secondary hypogonadism can further be categorized as:

Congenital hypogonadism - Hypogonadism present from birth.


Acquired hypogonadism - Hypogonadism that develops later in childhood, adolescence, or adulthood.

What are the risk factors for testosterone deficiency?


Some of the most common risk factors for developing testosterone deficiency are:

Increasing age








Low physical activity (Metabolic Syndrome)