Good question. One is hypertrophy of the prostate and the other is chronic inflammation either because of constant bacteria or cause unknown. Both cause urinary tract issues and discomfort. Those symptoms can be similar in both issues. Age can help determine which because prostatic hyperplasia happens usually in men over 50 and prostatitis happens usually in men under 50. Prostatitis can have other symptoms like fever, chills, pus like discharge, etc. You can also have erectile dysfunction with chronic prostatitis. Prostatic hyperplasia can cause the inability to urinate at all along with the overlapping symptoms of chronic prostatitis.
So, they have similar things but some differences. Which do you think you have?