What Is an Overactive Bladder? Definition and Symptoms              An overactive bladder (OAB) is a condition characterized by a sudden, uncontrollable urge to urinate. Symptoms often include frequent urination, nocturia (waking up multiple times during the night to urinate), and sometimes involuntary urine leakage (urge incontinence). How It Differs From Other Bladder Issues Unlike other urinary […]