Inability to Urinate Causes

The 2 essential causes of urinary retention are (1) blockage of the urethra and (2) disruption of the delicate and complex system of nerves that connects the urinary tract with the brain.

Acute conditions

• Blockage (obstruction): The most common cause of blockage of the urethra in men is enlargement of the prostate. In males, the prostate gland partially surrounds the urethra. If the prostate becomes enlarged, which is common in older men, it presses on the urethra and can block it. The most common cause of prostate enlargement is benign prostatic hypertrophy (often called BPH). Other causes of prostate enlargement include cancer and infection. Causes that can occur in both sexes include scar tissue, injury (as in a car wreck or bad fall), blood clots, infection, tumors, and stones (rare).
  
  
• Nerve problems: Disruption of the nerves between the bladder and the brain can cause you to lose control of your bladder function. The problem may lie in the nerves that send messages back and forth or in the nerves that control the muscles used in urination, or both. Some forms of this are called neurogenic bladder. Occasionally, urinary retention is the first sign of spinal cord compression, a medical emergency that must be treated right away to prevent permanent, serious disability. The most common causes of this disruption include spinal cord injury, spinal cord tumor, herniated disk in your back, or an infection or blood clot that places pressure on your spinal cord.
  
  
• Infection: An infection in your pelvic area, such as herpes, can interfere with nerves in the area. Inflammation and swelling caused by infections can also compress the urethra. Infections around the spinal cord can cause retention by placing pressure on the cord.
  
  
• Surgery: Urinary retention is a relatively common problem after surgery. It is a direct result of the anesthetic or the type of operation.

Medications

Certain medications can cause urinary retention, especially in men with prostate enlargement. Many of these medications are found in over-the-counter cold and allergy preparations.

• Drugs that act to tighten the urinary channel and block the flow of urine include ephedrine (Kondon’s Nasal, Pretz-D), pseudoephedrine (Actifed, Afrin, Drixoral, Sudafed, Triaminic), and phenylpropanolamine (Acutrim, Dexatrim, Phenoxine, Prolamine).
  
  
• Antihistamines such as diphenhydramine (Benadryl, Compoz, Nytol, Sominex) and chlorpheniramine (Chlor-Trimeton, Allergy 8 Hr), as well as some older antidepressants, can relax the bladder too much and cause urination problems.
  
  
• Caution: The ingredient phenylpropanolamine has been associated with stroke. The FDA is taking over-the-counter medications containing phenylpropanolamine off the market and asking their manufacturers to change them.

Urinary retention in children

• A child can have problems from birth that cause an inability to urinate properly. These problems usually become apparent within the first 6 months of life.
  
  
• A child may suddenly become unwilling to urinate. This is generally due to a temporary condition causing them pain with urination. Pain can be caused by a vaginal yeast infection in girls or an irritation from soap or shampoo used in bathing. Almost always, the child will eventually urinate without further help.

Chronic conditions

Chronic urinary retention usually develops slowly because the bladder does not empty completely. It may take a very long time to be diagnosed because you may not have any symptoms.

• A weak bladder muscle, chronic obstruction, and nerve diseases or injury all can contribute to chronic urinary retention.
  
  
• Chronic retention can lead to urinary incontinence (the unwanted leakage of urine from the bladder), urinary tract infection, and kidney failure.