OVERVIEW

What is Overactive Bladder Syndrome?

Overactive Bladder (OAB) is a symptom complex characterized by urinary urgency, often accompanied by frequent urination and nocturia, with or without urge incontinence. Urodynamically, it may manifest as detrusor overactivity or other forms of urethrovesical dysfunction.

OAB excludes symptoms caused by acute urinary tract infections or other localized bladder/urethral pathologies.

The exact etiology remains unclear and may involve multiple contributing factors. Severe cases can significantly impair quality of life.

Treatment options include behavioral interventions, medication, neuromodulation, and surgical procedures, with varying prognoses.

SYMPTOMS

What are the symptoms of overactive bladder?

An overactive bladder may exhibit the following symptoms:

• A sudden urge to urinate that is difficult to control;

• Urinary urgency, even leading to urge incontinence (the inability to hold urine long enough to reach a toilet after feeling the urge), with the ability to fully empty the bladder;

• Frequent urination—urinating 8 or more times in 24 hours despite normal fluid intake and total urine output;

• Waking up two or more times at night to urinate (nocturia);

If these symptoms are affecting your quality of life, seek medical attention promptly.

CAUSES

What are the causes of overactive bladder?

The exact cause of overactive bladder is not entirely clear. Conditions mentioned below, such as bladder stones or medications that increase urine output, cannot be classified as overactive bladder but may produce similar symptoms.

Several factors may contribute to overactive bladder or cause similar symptoms, including but not limited to the following:

• Neurological disorders, such as stroke and multiple sclerosis;

• Diabetes;

• Medications that rapidly increase urine production or require large amounts of fluid intake;

• Acute urinary tract infections, which can mimic overactive bladder symptoms;

• Bladder abnormalities, such as tumors, bladder stones, or foreign objects;

• Factors obstructing urine flow from the bladder: benign prostatic hyperplasia, constipation, or urethral stricture after trauma. These not only directly cause related symptoms but may also lead to incomplete bladder emptying and residual urine, reducing bladder capacity (storage space). Additionally, impaired bladder contraction due to various reasons may occur;

• Excessive consumption of caffeine or alcohol;

• Age-related cognitive decline, which may make it harder for the bladder to interpret signals from the brain;

• Difficulty walking, which may cause urgency if you cannot reach the bathroom quickly;

• In some cases, no specific cause can be identified even after thorough examinations.

What other conditions might overactive bladder lead to?

Long-term frequent urination, urgency, or incontinence can severely impact daily life, potentially leading to psychological or emotional issues, such as:

• Emotional distress or depression;

• Anxiety;

• Sleep disturbances and disrupted sleep cycles;

• Sexual problems, among others.

DIAGNOSIS

Which diseases have symptoms similar to overactive bladder?

• Urinary tract infection: Frequent urination, urgency, and dysuria are typical symptoms of a urinary tract infection (especially cystitis). It may also be accompanied by fever, lower back pain, fatigue, hematuria, etc. A urine test may show a large number of white blood cells and red blood cells, and a urine culture may reveal pathogenic microorganisms.

• Urinary tuberculosis: Symptoms such as frequent urination, urgency, and dysuria may also occur, and white blood cells may be detected in urine tests. However, conventional antibiotic treatment is ineffective. Acid-fast staining of urine samples can be performed to detect tuberculosis bacteria, along with laboratory tests such as tuberculosis DNA testing, tuberculin tests, and urine tuberculosis culture. Imaging tests like contrast studies or CT scans can also help confirm the diagnosis.

• Neurogenic bladder: Common in patients with diabetes, polio, stroke, or traumatic brain injury. Symptoms include frequent urination, urgency, difficulty urinating, or incontinence, possibly accompanied by constipation or fecal incontinence, loss of perineal sensation, or limb paralysis. Urine tests and cultures may be normal. Urodynamic tests may indicate detrusor hyperreflexia or areflexia. Additionally, neurological issues such as cognitive decline due to aging may disrupt communication between the brain and bladder, leading to similar symptoms.

• Factors obstructing urine outflow from the bladder: Conditions such as benign prostatic hyperplasia, constipation, or urethral stricture after trauma can directly cause related symptoms. Incomplete bladder emptying due to poor urine flow may lead to residual urine, reducing bladder capacity (storage space). Additionally, impaired bladder contraction function due to various reasons can contribute.

• Other causes include bladder abnormalities (e.g., tumors, stones, or foreign bodies), medications that rapidly increase urine production, excessive fluid intake in a short time, excessive consumption of caffeine or alcohol, or mobility issues that delay reaching the toilet, which may also cause bladder urgency.

What tests are needed when experiencing symptoms like frequent urination, urgency, or dysuria?

• Physical examination: Check for redness, swelling, or tenderness in the lower back or kidney area, assess whether an enlarged kidney can be felt in the upper abdomen, observe if the bladder is distended above the pubic symphysis, check for tenderness or masses, and examine the external genitalia and urethral opening for abnormalities.

• Urine test and culture: A urine test can indicate a urinary tract infection. The presence of white blood cells suggests infection, and further urine culture may be necessary.

• Imaging tests: Include urinary system ultrasound, urography, and cystoscopy.

• Urodynamic tests, etc.

How is overactive bladder diagnosed?

Doctors typically diagnose the condition based on the patient's symptoms and necessary tests to rule out other related diseases.

TREATMENT

Which department should I visit for overactive bladder?

Urology.

How is overactive bladder treated?

Treatment for overactive bladder includes behavioral interventions, medication, nerve modulation, and surgical options:

Behavioral interventions are important methods for managing overactive bladder. They are often effective and have no side effects. Specific approaches include:

• Bladder training: Delaying urination to gradually increase voided volume to over 300 ml. Not suitable for low-compliance bladders with detrusor pressure exceeding 40 cm H₂O at the end of filling.

• Scheduled voiding: Used for severe, uncontrollable incontinence to reduce episodes and improve quality of life. Not suitable for severe urinary frequency.

• Pelvic floor muscle exercises: Strengthening the pelvic floor muscles and urethral sphincter through targeted exercises.

• Healthy weight: Weight loss may alleviate symptoms if overweight. It may also help with stress incontinence.

Medications:

• First-line drugs: Tolterodine, Trospium, Solifenacin. These drugs work by:

  Antagonizing M receptors to inhibit detrusor contractions, improving bladder sensation and suppressing unstable detrusor contractions. Their high bladder selectivity makes them first-line treatments, ensuring efficacy while minimizing side effects.

• Other options:

  • Other M-receptor antagonists: Oxybutynin, Propiverine, Propantheline, etc. These may have more side effects due to action on non-bladder M receptors.
  • Sedatives/anti-anxiety drugs: Imipramine, Doxepin, Diazepam.
  • Calcium channel blockers: Verapamil, Nifedipine.
  • Prostaglandin synthesis inhibitors: Indomethacin.

Nerve modulation: Sacral neuromodulation may help with refractory urinary frequency, urgency, or urge incontinence.

Surgery:

• Indications: Only for severe low-compliance bladders, small bladder capacity threatening upper urinary tract function, and failure of other treatments.
• Procedures: Detrusor myotomy, etc., though rarely used.

Other treatments:

• Botulinum toxin A detrusor injections: Effective for severe detrusor overactivity.

• Intravesical RTX, hyaluronidase, or capsaicin: These modulate bladder sensory input and may help severe bladder hypersensitivity.

DIET & LIFESTYLE

What should patients with overactive bladder pay attention to in daily life and diet?

By adjusting daily lifestyle and habits, symptoms can be alleviated or relieved:

• Control weight or maintain a healthy weight, which helps reduce the risk of onset or alleviate symptoms.

• Do not restrict fluid intake. Insufficient water consumption can lead to concentrated urine, irritating the bladder lining and triggering the urge to urinate.

• Limit foods and beverages that may irritate the bladder. Potential bladder irritants include: caffeine, alcohol, apples, carbonated drinks, citrus juices and fruits, chocolate, corn syrup, cranberries, spicy foods, honey, milk, sugar, artificial sweeteners, tea, tomatoes, and vinegar.

• Aside from the aforementioned potentially irritating foods and drinks, there are no specific dietary restrictions. Maintain a balanced and nutritious diet.

PREVENTION

How to prevent overactive bladder?

Since the exact cause of this condition remains unclear, there are no definitive preventive measures. Maintain a healthy lifestyle in daily life, pay attention to personal hygiene, enhance cleanliness, ensure proper nutrition, follow a balanced diet, and engage in regular exercise.

Additionally, develop good bowel and urinary habits.