What is urodynamics?

Urodynamics is the investigation of the function of the lower urinary tract – the bladder and urethra – using physical measurements, such as urine pressure and flow rate as well as clinical assessment.
The assessment begins with a medical history and examination – which may, for example, reveal abnormalities within the lower abdomen or pelvis that are contributing to the lower urinary tract symptoms.
The patient is then given a urination (voiding) diary to be kept for three days, to document their fluid intake and output, including episodes of incontinence.

1. bladder capacity
2. the frequency of passage of urine
3. episodes of incontinence
4. getting up at night to urinate.

The diary can also outline other problems, such as excessive fluid intake.
A midstream specimen of urine is sent to the laboratory in order to exclude infection.
A pad test may be performed for women complaining of urinary incontinence. This test determines the severity of any incontinence and objectively demonstrates the symptom. The patient drinks 500ml of water and walks about performing normal everyday tasks, while wearing a pre-weighed pad.
The pad is then re-weighed and a gain of more than 1g per hour is taken to represent urinary incontinence.