How often should you urinate? Is it normal to get up at night? How much urine should remain in the bladder after you go?

There is no single answer that applies to every woman. A systematic review titled Normative Noninvasive Bladder Function Measurements in Healthy Women examined these questions by combining research on women without urinary symptoms or known bladder disorders.

The researchers reviewed 24 studies involving 3,090 women between the ages of 18 and 91. They looked at bathroom frequency, urine volume, bladder emptying and urine flow.

How Often Do Healthy Women Urinate?

The average woman in the studies urinated:

These findings suggest that healthy bladder habits vary more widely than many people realize. For example, urinating more than eight times a day does not automatically mean that someone has overactive bladder—especially when there is no urgency, leakage, pain or disruption to daily life. The research found substantial variation even among women considered healthy.

How Much Urine Does the Bladder Hold?

Across the studies, women produced an average of about 1,577 milliliters of urine over 24 hours. The average amount passed during an individual bathroom visit was about 245 milliliters.

However, urine volume varied considerably. Fluid intake, caffeine, medications, activity, climate and other health factors can all affect how much urine the body produces and how often someone needs to go.

What Is Post-Void Residual Urine?

Post-void residual, often called PVR, is the amount of urine left in the bladder after urinating. It is usually measured with a bladder ultrasound.

The average PVR in the review was only 12 milliliters. The estimated reference range was approximately 1 to 56 milliliters. This means that a small amount of urine remaining in the bladder can be normal.

A PVR measurement should not be interpreted by itself. Your clinician will also consider your symptoms, medical history and how much urine was in your bladder before you urinated.

What About the Strength of the Urine Stream?

A uroflowmetry test measures how quickly urine flows. In the reviewed studies, the average maximum flow rate was approximately 29 milliliters per second.

Flow rate is affected by how full the bladder is and how much urine is passed during the test. A lower or higher number does not necessarily indicate a problem on its own. Uroflowmetry results must be interpreted along with urine volume, symptoms and other clinical information.

The Most Important Takeaway: “Normal” Is a Range

The studies produced useful averages, but the results differed greatly between groups. Age, fluid and caffeine intake, medications, chronic health conditions, menstrual or menopausal status, physical activity, cultural habits and long-standing toileting patterns may all influence bladder function.

Because the researchers could not fully account for these differences, the numbers should not be treated as strict diagnostic cutoffs. A value outside one of these ranges does not automatically mean that something is wrong, and a value inside the range does not rule out a problem when bothersome symptoms are present.

Bladder health is not defined by numbers alone. Comfort, control, sleep, daily activities and overall quality of life are also important. The study’s authors concluded that more research is needed to establish reliable reference values for different groups of women, particularly at different ages.

Adapted from: Wyman JF, Zhou J, LaCoursiere DY, et al. Normative noninvasive bladder function measurements in healthy women: A systematic review and meta-analysis. Neurourology and Urodynamics. 2020;39:507–522.

This information is intended for general education and should not replace an individualized evaluation by a qualified healthcare professional.