Uroflowmetry is a simple, diagnostic screening procedure used to calculate the flow rate of urine, determining how fast the urine flows.

The test is noninvasive (there is no cut or incision made), and may be used to assess bladder and sphincter function.

It can detect if a person’s urine flow is slow and determine if it is due to an obstruction of the flow or a weakness of the bladder; but it cannot differentiate between both (only a urodynamic study can differentiate obstruction of the flow or a weakness of the bladder). It is done in an outpatient setting.

The study consists of a combination of uroflowmetry and ultrasound of the bladder (including the kidneys) before and after you pass urine. This is to detect and assess the urinary flow, any residual urine in the bladder after passing urine, and the extent of severity of urine flow.

The patient will be made to pass urine in privacy into a uroflowmetry machine and the flow rate and pattern is recorded, so as to have a good idea of the urinary problem.

The uroflow patterns can be noted by a continuous tracing which is recorded when the urine flows along the uroflowmetry machine. The urologist can determine the provisional diagnosis after the uroflowmetry.

Uroflowmeter to assess urine flow

Uroflowmetry tracing to assess urine flow

By analyzing the various uroflowmettry patterns, the urologist can have a good idea of the possible diagnosis.

By using various flow rate nomograms, the urologist can determine whether the flow is normal or slow, and whether it may be obstructed or not.

Ultrasonography of the bladder before and after passing urine will be done to assess the amount of residual urine left back in the bladder.

This will assess the Bladder Voiding Efficiency.