Overactive Bladder – Diagnoss, Symptoms, and Treatment

What is Overactive Bladder?

Overactive bladder is a medical condition characterized by the inability to control the start of urination.  There are 3 main types of urinary incontinence – urge incontinence, stress incontinence, and overflow incontinence.

Urge incontinence is described as going before you reach the toilet – this is usually due to an overactive bladder.  Stress incontinence is usually seen in women who have given birth as it is related to stretching of the muscles near the bladder.  Patients lose urinary control when they cough or bear down due to increased intraabdominal pressure.  Overflow incontinence occurs when the bladder is full of urine and the urine spills out because it has reached its filling capacity.  This usually occurs in men with benign prostatic hyperplasia – an enlarged prostate that blocks off or constricts the urethra, making it difficult for urine to exit the bladder.

What Causes Overactive Bladder?

Urinary incontinence is caused by variable factors depending on the type of incontinence.  Urge incontinence is usually due to an overactive bladder.  Patients have a sudden urge to go and often urinate prior to arriving at their bathroom destination.

Stress incontinence is usually seen in women who have given birth as it is related to pelvic relaxation.  When women give birth the anatomy of their urinary and gynecologic tract gets altered, particularly in relation to the stretched pelvic muscles and angle of the urethra.  Patients typically experience incontinence when bearing down, coughing, sneezing, or laughing.

Overflow incontinence occurs when the bladder is full of urine and the urine spills out because the bladder has reached its filling capacity.  This usually occurs in men with benign prostatic hyperplasia.  This may also occur in individuals with spinal cord injury in the setting of trauma or multiple sclerosis.

Risk factors for urinary incontinence include:

• Obesity
• Having given birth
• Vaginal birth delivery
• Older age 
• Family history

Urinary tract infections may cause urinary frequency and incontinence at times – this is always a consideration in anyone with the sudden onset of urinary incontinence.

How Common is Overactive Bladder?

Urinary incontinence is common in the United States. It is far more common in women, with 10% of women reporting symptoms of regular urinary incontinence. These symptoms are more common in women who are pregnant with 16% of women reporting symptoms of urinary incontinence during pregnancy. 

Symptoms of urinary incontinence in women are far more common in those who have given birth or are currently pregnant but these symptoms can still occur in women who have never been pregnant. 13% of women between the ages of 16-30 who have never been pregnant report symptoms of urinary incontinence. 

Male urinary incontinence is almost entirely related to enlargement of the prostate. 3% to 11% of men are estimated to experience symptoms of urinary incontinence. These patients are generally older with the majority being older than 65.

Signs and Symptoms

The key sign that defines urinary incontinence is the presence of urinary leakage at undesirable times. There are other more specific symptoms that also occur, the most common of these are:

• Urine leakage - With coughing, laughing, or physical exertion 
• Lack of control of urination
• Urinary frequency

Diagnosis

The diagnosis of urinary incontinence is generally made based on symptoms alone. The majority of the testing in patients with urinary incontinence is focused around searching for the cause of urinary incontinence. 

Your doctor will usually order a urinalysis and urine culture to evaluate for urinary tract infection – this is a common cause of incontinence, especially in the elderly.  In addition, they may obtain a CMP (comprehensive metabolic panel) and CBC (complete blood cell count).  They will also usually screen for diabetes which can lead to urinary frequency and contribute to incontinence.

Occasionally they will recommend obtaining an ultrasound of the bladder before and after urination to assess post-void residual volume, the amount of urine that remains in the bladder after voiding.  Post-void residual volumes of >200 mL are suggestive of urinary retention.  Your doctor may also recommend a CT scan of the abdomen, cystoscopy (to take a look inside the urinary tract), and sometimes urodynamic studies which analyze the pressures within the urethra and bladder.

Overactive Bladder Medication and Treatment

The first goal is to determine if there is another underlying reversible condition that is contributing to the patient’s symptoms.  This may include a urinary tract infection, BPH, or diabetes.  These conditions are typically treated before starting any specific therapies for urinary incontinence.

Urinary incontinence is treated with behavior techniques, medications, and occasionally surgery – depending on the type of incontinence.

Women with stress incontinence almost always benefit from Kegel exercises – these activities are intended to strengthen the floor muscle of the pelvis, thereby improving incontinence.  Patients that do not respond may benefit from placement of a pessary, an indwelling vaginal support that places pressure on the urethra, replacing the function of the weakened pelvic floor muscles.

Patients with urge incontinence can benefit from bladder training such as timed voiding to keep bladder volumes low and avoid incontinence.  Treatment may include medications that relax the bladder muscles such as Ditropan (oxybutynin).  Patients that do not respond to or cannot tolerate the side effects of antimuscarinic agents such as oxybutynin may benefit from Myrbetriq(mirabegron).

The treatment of overflow incontinence involves reversing whatever process that is causing the retention of urine in the bladder– this may be an enlarged prostate (BPH), spinal cord disease, or taking a medication that causes urinary retention.  BPH is typically treated with alpha blockers such as Flomax (tamsulosin).  Spinal cord disease severe enough to lead to urinary symptoms may require surgery to relieve pressure on the spin cord.  Certain medications with antimuscarinic activity may cause urinary retention and overflow incontinence – this may be seen with tricyclic antidepressants such as Elavil (amitriptyline).  These types of medications may actually be beneficial in patients with urge incontinence.