Urinary Bladder and Micturition

• First sensation of bladder filling at 100–150ml in an adult.
• Feeling of need to pee at 200 - 350 ml of urine
• Can comfortably hold between 300 - 450 ml
• Wall pressure of 5 - 15 mm Hg creates a sensation of bladder fullness while 30 mm Hg & beyond is painful.
• Most people pee 6 or 7 times/ 24 hours (4 -10 times daily is healthy).
• Normal 24-hour Urine output is 800 - 2000 ml/day (at normal fluid intake of about 2 liters/day).