If you're unable to empty your bladder, you are suffering from urinary retention (ischuria). You may be unable to begin, or unable to finish the job.
Acute (sudden onset) retention can happen to anyone at any time of life. However, it tends to happen less frequently in women than in men, and usually shows up around or after the age of sixty.
How do you know if you have this condition?
Oh, you'll know.
You may experience intense lower abdominal pain, and your abdomen may be distended (swollen). You will be unable to urinate properly, though you feel a powerful need to do so.
If you do manage to start a stream, it will be weak and will likely start and stop repeatedly. You may break out in a sweat, and find yourself writhing with the pain.
Obstructive urinary retention may originate with blockage in the bladder or the urethra (the tube carrying urine from the bladder out of the body) from a kidney stone or bladder stone.
Non-obstructive retention can be the result of spinal cord or nerve damage. Messages from the central nervous system aren't sent and received properly. The ability to control the muscles used for urination can be severely hampered.
This may be an indication of a spinal cord tumor, ruptured or herniated disk in the spine, stroke, diabetes, or a blood clot or infection pressing on the spinal cord.
Infection can cause inflammation and swelling, putting powerful pressure on the urethra, or on the nerves in the spinal cord or pelvis.
Acute urinary retention is a frequent after-effect of surgery, either from anesthetic, or from the surgery itself. Scar tissue from previous surgeries can complicate matters.
Use of allergy medication or cold remedies with decongestants or antihistamines will sometimes lead to acute urinary retention. This can also be true of some prescription drugs that can cause narrowing of the urethra, like albuterol, ephinephrine or ipratopium bromide.
Extended exposure to extremely cold temperatures can leave you more prone to developing this condition. Drinking too much alcohol can also be a risk factor.