The term azoospermia is used when there are no sperms in the semen. It should not be confused with aspermia, which means there is no semen. There are several causes for azoospermia. Hormone related causes like low FSH (Follicular Stimulating Hormone) or LH (Luteinizing Hormone); testicular causes like infections or genetic disorders; obstruction in the ducts that connect testis to the urethra may cause azoospermia. Diagnosis is made by testing semen, blood work for hormones and imaging studies of the testes. Treatment depends on the underlying cause. Testicular biopsy is performed to collect few sperms. These sperms may be used for artificial fertilization or ICSI (Intra Cytoplasmic Sperm Injection).
We researched this topic for you and found the following best online resources. They are categorized into basic, advanced, and research level based on the extent of information you need. You will be taken to the respective websites by pressing on the links below.