There are several different types of urinary catheter, which are inserted and used in different ways.
In most cases, intermittent urinary catheters are recommended. These catheters are inserted several times a day, for just long enough to drain your bladder, and then removed.
You should be taught how to insert the catheter yourself. It's usually inserted into your bladder through the urethra (the tube that carries urine out of your body).
The sterile catheter is usually pre-lubricated, to reduce the risk of any discomfort when you insert it.
One end of the catheter is either left open-ended, to allow drainage into a toilet, or attached to a bag to collect the urine. The other end is guided through your urethra until it enters your bladder and urine starts to flow.
When the flow of urine stops, the catheter can be removed. A new catheter is used each time.
An indwelling urinary catheter is inserted in the same way as an intermittent catheter, but the catheter is left in place.
The catheter is held in the bladder by a water-filled balloon, which prevents it falling out. These types of catheters are often known as Foley catheters.
Urine is drained through a tube connected to a collection bag, which can either be strapped to the inside of your leg or attached to a stand on the floor.
Indwelling catheters are sometimes fitted with a valve. The valve can be opened to allow urine to be drained into a toilet, and closed to allow the bladder to fill with urine until drainage is convenient.
Most indwelling catheters need to be changed at least every 3 months.
A suprapubic catheter is a type of catheter that is left in place.
Rather than being inserted through your urethra, the catheter is inserted through a hole in your tummy (abdomen) and then directly into your bladder. This procedure can be done under general anaesthetic, epidural anaesthetic or local anaesthetic.
A suprapubic catheter is used when the urethra is damaged or blocked, or when someone is unable to use an intermittent catheter.
The catheter may be secured to the side of your body and attached to a collection bag strapped to your leg. Alternatively, a valve can be attached that opens to allow urine to be drained into a toilet, and closes to allow the bladder to fill with urine until drainage is convenient.
This type of catheter is usually changed every 4 to 12 weeks.
Read more about living with a urinary catheter.