There are many possible reasons someone may suffer from bed wetting even as an adult.  Depending on what type of adult nocturnal enuresis someone suffers from the reasons for bed wetting may differ slightly.

Causes of Primary Nocturnal Enuresis (Adult Bed Wetting)

An adult who has wet the bed most of his or her adult life is said to have primary nocturnal enuresis (PNE).  This type of bed wetting could be caused by a condition that some people call “having a small bladder.”  In reality, the physical bladder is the same-sized as a normal person’s bladder, but the bladder of an adult bed wetter has a lower functional bladder capacity (FBC).  A lower FBC means that a person’s bladder sends a “full” signal to the brain earlier than it should.  A person’s physical bladder may not really be full, but the brain thinks it is and this causes unintended urination, often at night and when the person is sleeping.

A hormone imbalance could also be the culprit.  The antidiuretic hormone (ADH) is a hormone that tells the kidneys to produce less urine and often sends the signal at night and during sleep.  In some people an imbalance of ADH causes urine production to increase or maintain at daytime levels, making it difficult to go through a night without urinating or for some adults, wetting the bed.

The detrusor muscle in the body is responsible for “squeezing” the bladder to eliminate urine when the bladder is full.  When the muscle is relaxed the bladder can fill.  Some adult bed wetters has a detrusor muscle which is overactive or unstable and either doesn’t fully relax or spasms from time to time, squeezing the bladder.  Detrusor instability, along with a lower functional bladder capacity, is said to account for a large majority of adults who suffer from primary nocturnal enuresis.

Causes of Secondary Nocturnal Enuresis (Onset Adult Bed Wetting)

Adult onset bed wetting, or secondary nocturnal enuresis, can affect anyone after he or she has had a long period without any bed wetting problems.  Though often associated with aging and growing older, adult and even teens can begin wetting the bed for any number of reasons.  Here are some of the causes of secondary nocturnal enuresis among adults:

• Bladder issues, including cancer
• Some types of sleep apnea
• Diabetes
• Certain allergies
• Urinary track issues, including infections and stones
• Weakening/lax muscle tone
• Prostatitis/enlarged prostate in men
• Pelvic issues in women
• Overstimulation or excessive stimulation of sex organs
• Undiagnosed spinal cord or internernal injuries
• Taking certain insomnia and psychiatric medications (including thioridazine, risperidone and clozapine)
• Anxiety or emotional distress (rare)

New cases of adult bed wetting in otherwise healthy adults could be the symptom of a larger or more serious problem.  A thorough exam with a qualified medical professional is needed to help determine the underlying causes of most secondary adult bed wetting issues.  Often the symptom of bed wetting by adults is sometimes a flag for another problem such as certain types of cancer, internal injuries or abnormalities or even Type 2 Diabetes.  Curing the underlying problem will cease or decrease the frequency of bed wetting.

Alcohol and excessive caffeine from coffee or tea can also increase an adult’s chances of wetting the bed.  Drinking large quantities of liquid before bed time or taking medications with diuretic side effects will also increase the chances of accidental elimination for adults who are having issues with bed wetting.

Adult bed wetting may also be caused by genetics.  Some studies have shown a close correlation between parents and children who later took bed wetting into adulthood.  Adults who have two parents who also suffered from adult bed wetting may have an over 70% chance of suffering from bed wetting at some point in their own lives as well.