There are three main complications of a kidney infection. They are:
- kidney abscess
- blood poisoning
- severe infection
Kidney abscess
A kidney abscess is a rare but serious complication of a kidney infection. It's when pus develops inside the tissue of the kidney.
You're thought to be most at risk of developing a kidney abscess if you have diabetes.
The symptoms of a kidney abscess are similar to those of a kidney infection. The most common are:
- a high temperature of 38ºC (100.4ºF) or above
- chills
- abdominal pain
- loss of appetite
- pain when passing urine
Kidney abscesses are potentially serious because the bacteria inside the abscess can spread to other parts of your body, such as your bloodstream or lungs, and can be fatal.
Smaller abscesses can usually be treated with intravenous antibiotics. Surgery is usually required for larger abscesses. It normally involves draining the pus out of the abscess using a needle that's inserted into the kidney.
Blood poisoning
Blood poisoning is another rare, but potentially fatal, complication of kidney infection. It happens when bacteria spreads from the kidneys into the bloodstream. Once bacteria are in your blood, the infection can spread to any part of your body, including all of the major organs.
In someone with a kidney infection, the symptoms of blood poisoning, which is medically known as sepsis, include:
- low blood pressure, which makes you feel dizzy when you stand up
- confusion or disorientation
- excessive sweating
- uncontrollable shaking or shivering
- high temperature or, alternatively, a body temperature that's lower than usual; under 36ºC (96.8ºF)
- pale skin
- rapid heart beat
- breathlessness
Blood poisoning is a medical emergency that usually requires admission to a hospital intensive care unit (ICU) while antibiotics are used to fight the infection.
If you're taking certain medications for diabetes, such as metformin or angiotensin-converting enzyme (ACE) inhibitors, they may have to be temporarily withdrawn until you recover. This is because they can cause kidney damage during an episode of blood poisoning.
Severe infection
Another rare but potentially fatal complication of a kidney infection is a condition called emphysematous pyelonephritis (EPN).
EPN is a severe infection where the tissues of the kidneys are rapidly destroyed and the bacteria that are causing the infection begin to release toxic gas, which builds up inside the kidneys.
The exact cause of EPN is unclear, but almost all cases are in people with diabetes.
The usual treatment is emergency surgery to remove some, or all, of the affected kidney. It's possible to live a full and active life with only one kidney.
