Difficulty in urination in men can occur due to numerous reasons. The symptoms can be divided into storage symptoms, where a man is unable to hold the urine for long periods of time or has developed a very small bladder capacity.
There are also emptying symptoms, where the main issue is the inability to effectively empty the bladder with symptoms of obstruction such as hesitancy, intermittent urination, dribbling, repeated trips to the bathroom to urinate due to incomplete emptying the bladder, and post void dribbling.
There is an obvious overlap between these two types of voiding dysfunction. These symptoms can be caused by numerous issues, from symptoms related to generalized conditions such as strokes, seizures, and cancers of the central nervous system.

There are also causes that directly involve the bladder, urethra, and prostate such as BPH or benign prostatic hyperplasia, strictures or scars to the urinary tract, infection, stones, and cancers of the urinary tract.
It is recommended that patients with significant voiding dysfunction, especially if it is associated with pain, blood in the urine, or other major symptoms such as severe weight loss, be evaluated thoroughly to ensure that these are not caused by significant urinary conditions.