There are many things that could cause urinary retention, but there are two main causes: obstruction or non-obstruction (Urinary Retention Causes, symptoms). An obstruction is a blockage that impedes urine to flow out of the body. A cystocele, for example, is caused when the “rectum sags into the back wall of the vagina,” (Urinary retention causes & treatment) causing the urine to be stay inside the body. Non-obstructive causes include a weakened bladder muscle as well as nerve problems. Nerve causes can be very dangerous because it means the brain is unable to receive the message that the bladder is full and may lead to a stroke, diabetes, or even trauma to the spine or pelvis (Urinary retention causes & treatment). Drugs, surgery, infection and swelling, can also be other causes of urinary