Azoospermia is the complete absence of sperm in the neat and centrifuged sample of semen. It is always important to remember that the semen analysis has to be repeated at least twice if a diagnosis of Azoospermia is to be entertained. The Etiology of Azoospermia can either be Obstructive or Non-Obstructive.
In Obstructive Azoospermia there is an obstruction to the path the sperm travels from the testis to the penis. The obstruction could be in the testis, the epidydymis, the vas deferens (the vas could also be absent) or the ejaculatory duct.