What is Azoospermia?

Azoospermia is a medical condition where a man's semen contains no sperm. It can be caused by a number of factors, including: hormone problems, genetic conditions, previous vasectomy or other surgery, cancer treatments, and ductal obstruction.
Azoospermia can be classified as either obstructive or nonobstructive:
Obstructive
Sperm is produced by normal testicles but is not ejaculated due to a blockage in the genital tract.
Nonobstructive
The testicles and genital tract are normal but are not appropriately stimulated by the hormonal system to produce sperm.