Azoospermia
Azoospermia means no sperm are found in the ejaculate on two separate, centrifuged semen samples. It splits roughly 40% obstructive (a blockage) and 60% non-obstructive (a production problem), per AUA/ASRM guideline criteria.
Symptoms
Usually none beyond infertility itself; testicular size and consistency on exam can hint at obstructive versus non-obstructive causes.
Causes and risk
Obstructive causes include prior vasectomy, congenital absence of the vas deferens, or infection-related scarring. Non-obstructive causes include genetic conditions (Klinefelter syndrome, Y-chromosome microdeletions), hormonal problems, and prior chemotherapy or radiation.
How it is evaluated
A hormonal panel (FSH, testosterone), karyotype, Y-microdeletion testing, and CFTR gene testing (for suspected congenital absence of the vas deferens) round out the workup; testicular biopsy is reserved for cases where imaging and labs don't clarify the cause.
Treatment
Obstructive azoospermia can sometimes be surgically corrected or bypassed for sperm retrieval. For non-obstructive azoospermia, micro-TESE is the preferred sperm retrieval method, with roughly a 50% success rate depending on the underlying cause; testosterone monotherapy is specifically avoided since it further suppresses any remaining sperm production.
When to seek care
Azoospermia itself is not an emergency. Sudden testicular pain or a new mass are the findings that need prompt, separate evaluation.