"Many of us, after reaching a certain age, notice that we have to urinate more frequently and with more urgency. The standard assumption, that seems to have become part of our folklore, is that your bladder shrinks as you get older. We found that this may not be the case," said Neil Resnick, M.D., professor and chief, division of geriatric medicine, University of Pittsburgh School of Medicine.
In the study, the researchers compared data on a number of variables including bladder capacity and stability, urethral closure pressure, voiding flow rate and detrusor contraction strength from 95 females between the ages of 22 and 90. The researchers found that while bladder and urethral function deteriorate throughout adult life, bladder capacity rarely changes.
Women with normally aging bladders had weaker bladder sensation; while women who experienced increased bladder sensation actually had an underlying condition called detrusor overactivity (DO). DO is a common condition, often referred to as overactive bladder, where the detrusor muscle that controls the emptying of the bladder contracts involuntarily, creating a strong, sometimes uncontrollable urge to empty the bladder.
"Now, when a woman comes to her doctor and says that she thinks her bladder is shrinking, we realize that it is more likely she suffers from DO than from a smaller bladder," said Dr. Resnick. "The good news is that DO is treatable, so that any woman experiencing urgency or incontinence should see her doctor."
Over 17 million Americans suffer from overactive bladder, a condition that significantly affects the patient's quality of life. An estimated 80 percent of these patients do not seek help or treatment for this condition. Overactive bladder is characterized by the following conditions: frequency - urinating more than eight times in a 24 hour period; urgency - the immediate and strong urge to urinate; and, for some, urge incontinence - the inability to suppress urgency resulting in the leaking or loss of urine.
In addition to Dr. Resnick, Mathias Pfisterer from the University of Heidelberg, Germany and Werner Schaefer and Derek Griffiths from the University of Pittsburgh contributed to this research.
The research was funded by the National Institute on Aging, one of the National Institutes of Health.