Urinary incontinence is an embarrassing condition that causes urine to leak from the bladder when you do simple things like cough or sneeze. It also manifests itself as a sudden and strong urge to urinate, but is so sudden that you can't make it to the bathroom in time. Simple tests can be performed to determine the cause and subsequent treatment regimen.

Blood and urine

Blood and urine samples may be taken and sent to the lab for analysis. Urine can show infections, abnormalities and blood traces. Blood tests can reveal chemicals and other substances that could be the cause of your incontinence.

PVR

A post-void residual measurement (PVR) may be taken. In this procedure you urinate (void) into a container that can measure the output. Then using a catheter or ultrasound, your doctor checks the amount of urine remaining in your bladder. A large amount of urine can mean an obstruction in your urinary tract or a problem with your bladder nerves or muscles.

Pelvic ultrasound

A pelvic ultrasound checks your urinary tract and genitals for abnormalities.

Stress test

In the stress test your doctor has you cough and he checks for loss of urine.

Urodynamic testing

A urodynamic test checks the health of your urinary sphincter muscle and your bladder strength. Your doctor inserts a catheter into your urethra and bladder and fills it with water. A pressure monitor records the pressure in your bladder.

Cystogram

In a cystogram test, your doctor inserts a catheter in your urethra and injects dye into your urinary tract. As you urinate, an X-ray picks up the dye and reveals obstructions in your urinary tract if there are any.

Cystoscopy

In a cystoscopy, your doctor inserts a thin tube with a tiny lens attached to it into your urethra. Your doctor can then see any obstructions and remove them, if possible.

Source:

Mayo Clinic - urinary incontinence discussion