Testosterone is the most important male sex hormone. Testosterone not only controls development of the male sexual characteristics and the body's reproductive functions (sexual desire, erectile function, development of mature sperm). It also plays a decisive role in a man's mental and physical wellbeing and health.

A testosterone deficiency can cause a wide range of symptoms and serious diseases in men. If you notice signs of a testosterone deficiency, you should consult a doctor.

Many men are not sure how to go about finding a doctor. The family doctor is always a good place to start. However, there are also various specialists who deal with specifically male problems.

For diagnosis of a testosterone deficiency the doctor will carefully record any signs and symptoms and investigate possible causes.

If a testosterone deficiency is established, testosterone therapy can considerably improve mental and physical wellbeing, sexual satisfaction and quality of life. Diseases resulting from a testosterone deficiency (e.g. osteoporosis) can be prevented.