Risking it With Overactive Bladder

Overactive bladder causes and genetic risks

/ Author:  / Reviewed by: Joseph V. Madia, MD

Bladder function is probably something most people take for granted, but for those with overactive bladder, this situation takes on greater importance.

New research is exploring how the bladder works, who might be at a greater risk for developing bladder issues and how to treat such problems when they arise.

Normal Bladder Function

According to the Mayo Clinic, bladder function is a process managed by a variety of different factors, including the nerves, muscles and kidneys.

In normal cases, after urine is produced in the kidneys, it flows down to the bladder, which expands to hold the fluid. It then drains through the bottom of the bladder and exits the body through the urethra.

Typically, when the bladder is about a third of the way full, the nervous system begins to activate and communicate with the brain. The urge to urinate grows stronger as the bladder continues to fill.

The process of urinating itself involves more nerve signals, the relaxation of some muscles and the contraction of others.

Overactive Causes

The Mayo Clinic reports that most overactive bladder symptoms stem from the involuntary contraction of bladder muscles, causing the sensation of a very urgent need to visit the bathroom and urinate. Despite this sensation, there may be no physical need to go.

There may be various causes behind these symptoms, including other bladder issues like stones or tumors. Some urinary tract infections can also cause symptoms that are very similar to overactive bladder.

Neurological issues like strokes or Parkinson's disease can also be connected to overactive bladder.

High fluid intake, diabetes or problems with kidney function can cause high levels of urine production, as can medications that require drinking large amounts of fluids, or medications that themselves produce large amounts of urine. High levels of alcohol or caffeine intake can effect symptoms as well.

Issues like constipation, previous surgeries or enlarged prostates can sometimes block the outflow of urine from the bladder.

According to the Mayo Clinic, sometimes the precise cause of bladder issues may be unknown.

Genetic Risks

The Mayo Clinic reports that while overactive bladder may be more common among older people, it isn't a normal or expected part of aging.

Older people do have a greater risk of the condition, partly because they also have a greater risk for conditions like diabetes and enlarged prostate, which themselves can contribute to overactive bladder.

A 2011 study out of Sweden, published online by European Urology, explored a different potential risk factor in the development of overactive bladder and other urinary control problems - genetics.

The study, led by Anna-Lena Wennberg, PhD, of the University of Gothenburg looked at 25,364 twins between the ages of 20 and 46 years old from the Swedish Twin Registry.

The twins were surveyed regarding the presence of lower urinary tract symptoms like overactive bladder and urinary incontinence.

The rates of these symptoms were found to be higher in women.

The data was analyzed and the differences and variation between symptoms in identical twins and non-identical twins compared. (Identical twins share identical genes, while non-identical twins do not.)

The researchers found potential genetic connections in several of the lower urinary tract symptoms measured.

"With urinary incontinence, we saw that just over half of the variation (51 percent) can be explained by genetic factors. This doesn't mean that half of all people with urinary incontinence inherit it from their parents, but that around 50 percent of people's susceptibility to urinary incontinence can be explained by their genes," said Dr. Wennberg.

A connection between genes and the need to wake up during the night to go to the bathroom (called nocturia) was also seen, as 34 percent of the variation was attributed to genes.

The authors attribute the presence of the condition to a variety of factors, and as such suggest that treatment options that look at environmental factors continue to be the focus in treating overactive bladder.

Treating Externally

As the authors in the Swedish twin study suggested, treatments that focus on external or behavioral factors are often the first line of defense against overactive bladder.

Doctors will help in suggesting different strategies for different patients, but there are several methods commonly used.

Scheduling trips to the bathroom instead of going every time the urge is felt is one way to manage the condition.  Many with overactive bladder also try to train their bladder by gradually increasing the waiting time between feeling the urge and visiting the bathroom over time.

Controlling and watching the amount and timing of fluid intake is helpful for some patients, as are exercises (called Kegels) that strengthen the pelvic floor muscles. 

Medications and surgery can also help some patients control their overactive bladder symptoms.  Again, a doctor will help each individual patient manage their unique situation and symptoms.

As more research is completed and more is learned about the complex nature of bladder control issues, new strategies will likely be developed and honed, hopefully making overactive bladder easier to manage.

Review Date: 
September 30, 2012