Obstruction of Urine

• Urine flushes germs from the body, but bacteria can proliferate when the flow of urine is slowed or stopped by an obstruction such as an enlarged prostate gland or kidney stone.
  
  

Catheters

• Repeated catheterization (tubes inserted into the urinary tract) can allow germs to enter the bladder through the urethra and then multiply. Elderly people and those who have lost bladder control and need frequent catheterization often develop urinary infections.
  
  

Lowered Immunity

• Diseases that suppress the immune system make you more vulnerable to repeated infections, including bladder infections. For example, a disease like diabetes can make you more susceptible.
  
  

Female Anatomy

• Women are more prone to urinary tract infections than men. This is because of women's shorter urethra, which allows germs easier access to the bladder. A woman's urethra is also located close to the vagina and anus, which can be sources of bacteria.
  
  

Birth Control Methods

• Women using diaphragms and whose partners use condoms with spermicidal foam may be more prone to urinary tract infections.