An inability to urinate, or urinary retention, usually presents itself in men due to a blockage of the urinary tract from an enlarged prostate gland. Another common cause can be nerve damage. However, in both men and women, in all likelihood the reason behind urinary retention is an infection.
Urinary retention can be caused by urinary tract infections due to the nature of what infections due, and that is cause inflammation. When this occurs, the walls of certain parts of the urinary tract can compress and constrict, which causes a blockage. However, in some extreme cases when the infection spreads, it can cause swelling around the spinal cord, which can cause nerves to malfunction.