If you have an overactive bladder, you may: 
Feel a sudden urge to urinate that's difficult to control
Experience unintentional loss of urine immediately after an urgent need to urinate (urgency incontinence)
Urinate frequently, usually eight or more times in 24 hours
Wake up more than two times in the night to urinate (nocturia)
 Even if you are able to get to the toilet in time when you sense an urge to urinate, unexpected frequent urination and nighttime urination can disrupt your life.