There are many types of urinary tract infections, which can affect any part of the system, including the ureters, bladder, urethra, and even the kidneys. When the kidneys become involved, this is called pyelonephritis, and it is a very serious infection that should be treated as soon as possible.
What causes Pyelonephritis?
Because the urinary system is created to void the body of bacteria, waste, and toxins, it’s also set up to typically refuse entry of contaminants into the body. However, it’s possible in some circumstances for bacteria to make their way into the urethra and travel up to the bladder. This causes inflammation, and eventually, if left untreated, or if aggressive, it can also make its way up to the kidneys, causing pyelonephritis.
There are also other ways a kidney infection can form. For example, a patient with kidney stones can experience an infection, as people who have some sort of structural issue within the urinary tract or those with tumors in or around the urinary tract. These conditions can cause narrowing of the urethra and pressure on other organs in the system, all of which make it difficult to expel urine. With excess urine remaining in the bladder, bacteria has a chance to grow and can again reach the kidneys.
Risk factors for Pyelonephritis
Like most infections and conditions, there are risk factors which make it more likely a person will develop a UTI and especially a kidney infection, such as:
- Gender. Women have a shorter urethra, so bacteria have less distance to travel. In addition, the urethra being so near the vagina presents greater opportunity for bacteria to spread.
- Blockage. Anything that stands in the way of emptying the bladder or slows the flow of urine can cause a backup in the urinary structure and lead to a greater risk of infection.
- Weak immune system. If the immune system is weak, it can’t easily fight off the bacteria that causes such infections. High risk individuals with lowered immune systems include those with diabetes, HIV, and people on immunosuppressants for an immunodeficient disease or to avoid the rejection of transplants.
- Nerve damage. When there is nerve damage around the bladder or other organs of the urinary tract, there may be less capability of normal functionality, including the inability to feel the need to urinate or the inability to empty the bladder. This lack of control can make it a breeding ground for bacteria that spreads to the kidneys.
- Catheterization. Because a catheter irritates the urethra and bladder, it can lead to inflammation and even tissue damage, allowing penetration of bacteria that will then spread back into the kidneys.
- Vesicoureteral reflux. This is a condition that causes urine to flow back into the bladder from the urethra, essentially flowing the wrong way, which again, leads to urine backup that breeds excess bacteria.
Complications of Pyelonephritis
Other kidney functions essential to health include:
- Regulating blood pressure
- Regulating red blood cells
- Maintaining a balance of fluids
- Keeping electrolyte levels normal, such as potassium, sodium, magnesium, calcium, and acid
- Kidney scarring can lead to problems such as chronic kidney disease, as well as elevated blood pressure and, in some cases, even cause kidney failure.
- Septicemia, or blood poisoning, can occur due to reduced kidney functionality. When the kidneys cannot properly filter the blood, waste may be pushed back into the bloodstream. In addition, the bacteria causing the infection could spread through the blood, causing infections in other parts of the body, including the heart.
- Women who are pregnant and develop a kidney infection increase the risk of having a child with a dangerously low birth weight. They also risk needing dialysis for kidney failure after birth.
Symptoms of Pyelonephritis
While most urinary tract infections result in some pain and a burning sensation while urinating, kidney infections are far worse in terms of being symptomatic. Patients will feel quite ill and will likely experience some or all of the following:
- Frequent and urgent need to urinate
- Painful urination
- Abdominal pain
- Back, flank, and groin pain
Diagnosis and treatment of kidney infections
To diagnose pyelonephritis, doctors will take a patient history and perform a physical exam. Typically, they will request a urine sample for analysis and culture. Sometimes, a CT scan or kidney ultrasound will be performed, and they may want to perform a test that looks at how much urine remains in the bladder after the patient voids urine.
Treatment usually involved a round of antibiotics, typically as a pill prescribed to be taken at home over the course of two weeks, which is far longer than the typical UTI (for which antibiotic treatment usually spans only three to seven days). However, in severe infections, especially if the patient is vomiting, the physician may suggest a hospital stay for intravenous antibiotics and fluids. An additional culture may be taken after the antibiotics are finished to assure the infection is gone.
In some cases, where blockages and birth defects are the culprit behind the infection, surgery may be required. This can remove kidney stones and other blockages and repair naturally occurring blockages, such as birth defects, to reduce the possibility of future infections.