overactive bladder

Overactive bladder is a clinical syndrome defined by the International Continence Society as urgency with or without urge urinary incontinence, usually with increased daytime frequency and nocturia, in the absence of urinary tract infection or other obvious pathology. The pathophysiology involves detrusor muscle overactivity, which can be neurogenic (due to neurological conditions like stroke, multiple sclerosis, or spinal cord injury) or non-neurogenic (idiopathic). The condition results from abnormal bladder contractions during the filling phase, leading to sudden, intense urges to urinate. Key symptoms include urgency (sudden, compelling desire to urinate), frequency (>8 voids per day), nocturia (≥2 voids per night), and urge incontinence in some patients. Diagnosis is primarily clinical, supported by voiding diaries and urodynamic studies when indicated. Treatment includes behavioral modifications (bladder training, pelvic floor exercises), pharmacotherapy (antimuscarinics like oxybutynin, tolterodine; beta-3 agonists like mirabegron), and advanced therapies (botulinum toxin injection, sacral neuromodulation, percutaneous tibial nerve stimulation).