Testosterone is very important for a man as these are responsible for the sex drive, erection, production of sperms and facial hair. Low testosterone can result in a loss of sexual drive.
Low testosterone can be caused by several factors like obesity, aging, inflammation or infection. It can also be caused by an injury to testicles or by the use of certain performance enhancing drugs commonly used by athletes. Some medicines are also known to cause low testosterone. An injury to the head or high level of iron in blood can result in low testosterone.