A catheter is used to relieve urine by inserting a tube into the urinary tract until it reaches the bladder, according to MedlinePlus. After cleaning the area, females insert the sterile catheter into the urethra slowly until urine begins to flow. For males, the sterile catheter is inserted directly into the penis until urine flows.
Clean, intermittent catheterization is a form of catheterization that is removed from the body after the bladder is drained, reports MedlinePlus. This is only one kind of catheter used in the medical field.
A second type of catheter is an indwelling catheter, which remains in the bladder, and the urine is drained into a collection bag. Side effects of long-term indwelling catheters include fever, pain in the abdomen and changes in urine such as smell or color, according to InteliHealth. These side effects must be monitored carefully and reported to a doctor or caretaker if seen.
There is also a cardiac catheter, which uses the same concept as a urinary catheter, reports the National Heart, Lung, and Blood Institute. After a catheter is Inserted from a blood vessel in the groin, neck or arm and then into the heart, tests and treatments can be performed. During cardiac catheterization, an ultrasound of the heart is performed, after insertion of a dye, to look for plaque buildup in the arteries.