Each day in the United States, approximately 9 people are killed and more than 1,000 injured in crashes that are reported to involve a distracted driver. 1 Distracted driving is driving while doing another activity that takes your attention away from driving.
This is called the post-void residual. The bladder has a approximately 500ml capacity. You should feel a desire to void at ~250ml. Urinary retention is measured by using a special type of ultrasound (bladder scan), or by inserting a bladder catheter and measuring how much urine comes out. I'm a 4th year US med student. On one of my urology rotation I asked the Sr. resident this exact question.
A Dr. Jill Rabin , OBGYN (Obstetrics & Gynecology), answered. The bladder can hold anywhere between twelve and twenty ounces of fluid, depending on the age of the person. Bladder capacity tends to decrease with age and leads to an increased frequency of urination. It is not uncommon to feel the urge to urinate when the bladder holds just eight ounces of urine, and the bladder is generally emptied when it contains anywhere up to sixteen fluid ounces.