Most people think testosterone deficiency only occurs in elderly males or the frail or smaller stature men. Quite the opposite is true in fact. The men who come into my practice with testosterone deficiency usually present with a myriad of symptoms, including fatigue, inability to concentrate, muscle weakness, and high cholesterol. It is less often that I see the classic low testosterone symptom of decreased libido. So if you have similar symptoms, you might want to take a look at this list (in no particular order) of health conditions which have been scientifically shown to reduce testosterone levels in men of all ages and of all health status.