Symptoms of enlarged prostate include a urinary stream that is slow, weak or intermittent; difficulty beginning urination; and feeling that the bladder has not emptied after urinating, notes WebMD. People with enlarged prostates often get up several times at night to urinate.
As the prostate gets larger, it gradually blocks urinary flow at the urethra, the tunnel that sends semen and urine out of the body. As the urethra gets narrower, the bladder has to work harder to excrete urine. This can make the bladder muscle stronger, thicker and more sensitive as time goes by, to the point where the bladder contracts when just a little urine is inside, making the sufferer urinate more often. After enough time goes by, the bladder muscle is defeated by the narrowing of the urethra, so urine stays inside the bladder, and the bladder never completely empties, as stated by WebMD.
A bladder that always has old urine inside it is at high risk for harboring a urinary tract infection. Other problems, such as urinary blood, bladder stones, an inability to urinate and incontinence can happen as well. A man who loses the ability to urinate at all should seek emergency medical attention. In some cases, an enlarged prostate can eventually cause damage to the kidneys and/or bladder, reports WebMD.