What happens to prostate in non bacteria prostatitis? What cause this? Why cant void urine without alpha blocker medicine? Thanks

Usually not serious. Usually nothing important "happens" to the prostate. Nonbacterial or "nonspecific" prostatitis, also called chronic pelvic pain syndrome, is generally an issue of comfort; serious harm is uncommon. Continue to work with your doctor if you're having such serious symptoms that you cannot void without an alpha blocker, or only with marked obstruction. Google CPPS for more info (spell it out).