Urodynamics is the investigation of the function of the lower urinary tract to diagnose the reason for bladder dysfunction. This test is advised in patients with symptoms of urine leakage, frequent urination, recurrent urinary infections, pain during urination, sudden urge to urinate and problem in starting urination or completely emptying the bladder.
The lower urinary tract includes:
- Bladder: A muscular balloon like organ in the pelvic region that stores the urine
- Urethra: The tube connected to the bladder through which the urine flows out of the body
- Sphincters: These are the muscles in the urinary bladder that help in holding the urine in the bladder. They relax in coordination with the bladder muscle that tightens on signals from the brain and lead to release of the urine through the urethra to outside the body.
Urodynamic testing looks at how the coordinated functioning of the bladder, sphincters and urethra helps in storing and releasing the urine. Urodynamic testing includes:
- Uroflowmetry: Uroflowmetry measures the flow rate and volume of the urine. Abnormal results indicate either a problem in the bladder muscles or block in urine flow.
- Post void residual measurements: These measure the urine left in the bladder after urination.
- Cystometric test: Cystometric test measures the volume of the urine and the bladder pressure that causes the urge to urinate.
- Leak point pressure measurements: These measure the bladder pressure that involuntary causes urine to leak in the cystometric test.
- Pressure flow study: This determines the flow rate at a given pressure.
- Electromyography: Electromyography measures the electrical activity of the muscles and nerves in and around the bladder and sphincter.
- Video urodynamic tests: These give pictures and videos of filling and emptying of the bladder. Imaging is done either using X-rays or ultrasound.
Some of these tests are non-invasive while others require the insertion of a catheter into the bladder after giving local anaesthesia. You may feel a little discomfort when urinating for a few hours after the test. Drinking water often and holding a warm damp cloth over the urethral opening helps reduce the discomfort.