What is it?
Does it feel like you're always hurrying to the bathroom, afraid that you won't make it on time? Do you have trouble sitting through meetings or social functions without taking a restroom break? If so, you may have an overactive bladder.
Overactive bladder is a problem with bladder function that causes a sudden urge to urinate. The urge may be difficult to suppress, and overactive bladder can even lead to the involuntary loss of urine (incontinence).
If you have overactive bladder, you may feel embarrassed, isolate yourself, or limit your work and social life. The good news is that after a brief evaluation to determine the cause, you can receive treatments that may greatly alleviate symptoms of overactive bladder and help you manage their impact on your daily life.
Signs and symptoms of overactive bladder may mean you:
- Feel a strong, sudden urge to urinate
- Experience urge incontinence, the involuntary loss of urine immediately following an urgent need to urinate
- Urinate frequently, usually eight or more times in 24 hours
- Awaken two or more times in the night to urinate (nocturia)
Although you may be able to get to the toilet in time when you sense an urge to urinate, frequent and nighttime urination, as well as the need to suddenly "drop everything," can definitely disrupt your life.
Filling and emptying your bladder is a complex interplay of kidney function, nerve signals and muscle activity. A problem anywhere throughout this system can contribute to overactive bladder and urge incontinence.
Normal bladder function
Your kidneys produce urine, which travels down a pair of long tubes from your kidneys to your bladder. Urine drains from your bladder through an opening at the bottom (neck) and flows out a short tube called the urethra (u-REE-thrah). In women, the urethral opening is located just above the vagina. In men, the urethral opening is at the tip of the penis.
Your bladder expands like a balloon to accommodate the flow of urine. When it's reached about half its capacity, nerve signals alert your brain, and you sense that your bladder is "full." By the time it's three-quarters full, you feel the need to urinate (void). When you urinate, nerve signals coordinate the relaxation of the pelvic floor muscles and the muscles surrounding the neck of the bladder and upper portion of the urethra (urinary sphincter muscles). The muscles of the bladder contract, forcing urine out.
Involuntary bladder contractions
The symptoms of overactive bladder occur in most cases because the muscles of the bladder involuntarily contract. This contraction creates the urgent need to urinate. The urinary sphincter may remain constricted and prevent the bladder from leaking. If the sphincter's strength is overwhelmed by the contraction, then a person experiences urge incontinence.
Causal or contributing factors
In many cases doctors can't exactly identify the causes of overactive bladder. Neurological disorders, such as Parkinson's disease, strokes and multiple sclerosis, are often associated with an overactive bladder.
Several factors may cause or contribute to symptoms similar to those of overactive bladder, and your doctor will try to rule them out during an evaluation because they require other specialized treatments. These factors include:
- High urine production as might occur with high fluid intake, poor kidney function, or diabetes
- Acute urinary tract infections that can cause symptoms very similar to an overactive bladder
- Inflammation of tissues near the urinary tract
- Abnormalities in the bladder, such as tumours or bladder stones
- Factors that obstruct bladder outflow — enlarged prostate, constipation or previous operations to treat other forms of incontinence
- Excess consumption of caffeine or alcohol
- Medications that cause a rapid increase in urine production or require that you take them with lots of fluids
As you grow older, you're at increased risk of developing overactive bladder, and you're also more susceptible to diseases and disorders that can contribute to problems with bladder function, such as enlarged prostate and diabetes. Although common among older adults, overactive bladder and urge incontinence shouldn't be considered a normal part of aging.
As might be expected, urge incontinence can affect your overall quality of life, but frequent urination and nocturia can also be detrimental to your well-being. People with significant disruption from an overactive bladder are more susceptible to:
- Emotional distress
Some people may also have a disorder called mixed incontinence, when both urge incontinence and stress incontinence occur. Stress incontinence is the loss of urine when you exert physical stressors or pressure on your bladder, as when you cough or laugh.
In a basic diagnostic workup, your doctor will look for clues that may also indicate contributing factors. The exam will likely include:
- A medical history
- A physical examination with particular focus on your abdomen and genitals
- A urine sample to test for infection, traces of blood or other abnormalities
- A focused neurological exam that may identify sensory problems
Your doctor may order urodynamic tests, which are used to assess the function of your bladder and its ability to empty itself steadily and completely. These tests usually require a referral to a specialist in urinary disorders in men and women (urologist) or urinary disorders in women (urogynecologist). Tests include:
- Measurements of postvoid residual urine. When you urinate or experience urinary incontinence, your bladder may not empty completely. The remaining urine volume (postvoid residual urine) may cause symptoms identical to an overactive bladder. To measure residual urine after you have voided, a thin tube (catheter) is passed through the urethra and into your bladder. The catheter drains the remaining urine, which can then be measured. Alternatively, a specialist may use an ultrasound scan, which translates sound waves into an image of your bladder and its contents.
- Uroflowmetry. A uroflowmeter is a device into which you urinate to measure the volume and speed of your voiding. This device translates the data into a graph of changes in your flow rate.
- Cystometry and pressure-flow studies. Cystometry measures bladder pressure during filling. Pressure-flow studies measure the amount of pressure needed to urinate and the speed of the urine flow. A catheter is used to fill your bladder slowly with water. Another catheter with a pressure-measuring sensor device will be placed in your rectum or for women, in your vagina. This procedure can identify any involuntary muscle contractions, indicate the level of pressure at which you feel an urge or experience leakage, and measure pressure needed to empty your bladder.
- Electromyography. Electromyography assesses the coordination of nerve impulses in the muscles of the bladder and the urinary sphincter. Sensors are placed either on or in the skin in your pelvic floor.
- Video urodynamics. These procedures use either X-ray or ultrasound waves to create pictures of your bladder in combination with cystometry and a pressure-flow study as your bladder is filling and emptying. Your bladder is filled with the use of a catheter, and you urinate to empty your bladder. The fluid will contain a special dye that's detected by X-ray technology.
- Cystoscopy. A cystoscope, a thin tube with a tiny lens, enables your doctor to see the inside of your urethra and bladder. With the aid of this device, your doctor can check for abnormalities in your lower urinary tract, such as bladder stones or tumours.
Your doctor will review the results of these tests with you and suggest a treatment strategy.