Factors that increase your risk of a kidney infection include:

  • Female anatomy. Women have a greater risk of kidney infection than do men. A woman's urethra is much shorter than a man's, so bacteria have less distance to travel from outside the body to the bladder. The proximity of the urethra to the vagina and anus also creates more opportunities for bacteria to enter the bladder. Once in the bladder, an infection can spread to the kidneys.
  • Obstruction in the urinary tract. Anything that impedes the flow of urine or reduces your ability to completely empty your bladder when urinating, such as a kidney stone, structural abnormalities in your urinary system or, in men, an enlarged prostate gland, can increase your risk of kidney infection.
  • Weakened immune system. Medical conditions that impair your immune system, such as diabetes and the human immunodeficiency virus (HIV), increase your risk of kidney infection. Certain medications, such as drugs taken to prevent rejection of transplanted organs, have a similar effect.
  • Damage to nerves around the bladder. Nerve or spinal cord damage may block the sensations of a bladder infection so that you're unaware when it's advancing to a kidney infection.
  • Prolonged use of a urinary catheter. Urinary catheters are tubes used to drain urine from the bladder. You may have a catheter placed during and after some surgical procedures and diagnostic tests. A catheter may be used continuously if you're confined to a bed.
  • A condition that causes urine to flow the wrong way. In vesicoureteral reflux, small amounts of urine flow from your bladder back up into your ureters and kidneys. People with vesicoureteral reflux may have frequent kidney infections during childhood and are at higher risk of kidney infection during childhood and adulthood.
Aug. 09, 2011