A urinary catheter is a thin flexible hollow tube that drains urine from the bladder into a drainage bag and is a closed system. The catheter is inserted into the bladder either through the urethra (genital area) or through a small hole made in the abdomen (suprapubic). The catheter is held in place by a small balloon filled with sterile water. Each time a break is made in the closed system (e.g., changing a catheter bag) it is the opportunity for infection to be introduced. Good infection control practices are therefore essential.