Put simply, Andropause is caused by too little free testosterone and too much estrogen.  With receptor sites in several organs and throughout the body, testosterone is critical in maintaining healthy bone density, lean muscle, and red blood cell production.  Furthermore, testosterone is vital for proper cardiac output and neurological function.

When a man’s testosterone levels are low, it may result inthe body switching off some of the normal activity of the testes.  Once this happens, the body’s testosterone is increasingly converted to estrogen.

Simultaneously, another factor in the body, Sex Binding Hormone Globulin (SHBG), is increasing. SHBG is a protein that binds to the testosterone, and traps a lot of the testosterone that is still circulating and stops it from exerting its effects within the body. The testosterone that is left over after this process is known as “available” testosterone, and it is this available testosterone that does the beneficial work throughout the body.

Andropause is associated with low available testosterone levels. Every man experiences a decline of available testosterone with age, but some men's levels dip lower than others. It is when available testosterone levels dip low that these men can experience andropausal symptoms .

These symptoms can impact a man’s quality of life and may expose him to other, longer-term risks of low-testosterone.