The purpose of the male bladder is to store urine until a man chooses to urinate. During urination, urine passes from the bladder to the urethra, which is a tube that runs through the penis. The male urethra is much longer than the female urethra, according to WebMD.
In men and women, the bladder is a muscular, pear-shaped organ located in the pelvis. The kidneys make urine which passes through two tubes, called uterers, to the bladder, which stores the urine until the man chooses to expel it through the penis. When a man urinates, two sphincters open to allow urine to pass into the urethra, and the bladder muscles contract to help push out the urine. In men who suffer from an overactive bladder, these muscles can contract involuntarily, leading to urinary incontinence, according to WebMD. These muscles do not contract enough in men with urinary retention, causing the bladder to swell.
A normal female or male bladder can store between 400 and 600 milliliters of fluid, according to WebMD. Several medical conditions can cause men to need to urinate frequently. For example, cystitis, which is an inflammation or infection of the bladder, can cause men to have to urinate more often than usual as well as causing pain or discomfort.