Pyelonephritis
What is Pyelonephritis?
Pyelonephritis is a serious kidney infection that starts in the lower urinary tract and moves up to one or both kidneys. This bacterial infection causes inflammation and tissue damage in the kidneys. It happens when bacteria, usually E. coli from the bowel, enter the urinary tract and travel upward.
Unlike a simple bladder infection, pyelonephritis affects the kidney tissue itself. This makes it a medical emergency that needs quick treatment. Without proper care, the infection can spread to the bloodstream or cause permanent kidney damage. Most people recover fully with antibiotics, but early detection matters.
The condition affects about 15 to 17 out of every 10,000 women each year. Women are far more likely to develop pyelonephritis than men because of anatomy differences. People with diabetes, kidney stones, or weakened immune systems face higher risk.
Symptoms
- Fever, often high and sudden, sometimes with chills
- Pain in the back, side, or groin area, usually on one side
- Nausea and vomiting
- Frequent, painful urination
- Cloudy, dark, or bloody urine with a strong smell
- Urgent need to urinate
- Confusion or mental changes, especially in older adults
- Fatigue and general feeling of being unwell
Some people experience only mild symptoms at first. Children and elderly adults may not show typical signs. They might only have fever or confusion without obvious urinary symptoms.
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Causes and risk factors
Pyelonephritis usually happens when bacteria from a bladder infection travel up the ureters to the kidneys. E. coli bacteria from the digestive tract cause about 80 to 90 percent of cases. Sexual activity, holding urine too long, and improper wiping technique can push bacteria into the urinary tract. Once bacteria reach the kidneys, they multiply quickly and trigger inflammation.
Several factors raise your risk of developing this kidney infection. Women have shorter urethras, making bacterial travel easier. Pregnancy, kidney stones, and urinary catheter use create physical blockages. Diabetes and immune system problems make it harder for your body to fight infections. Nerve damage from conditions like multiple sclerosis can prevent complete bladder emptying. Structural problems in the urinary tract since birth also increase risk.
How it's diagnosed
Doctors diagnose pyelonephritis through urine tests that check for bacteria, white blood cells, and blood. A urine culture identifies the specific bacteria causing infection. This helps doctors choose the right antibiotic. Blood tests check for signs of infection spreading into the bloodstream. Imaging tests like ultrasound or CT scans may be used to look for kidney stones or structural problems.
Rite Aid offers testing that can detect blood in your urine, one of the key markers of kidney infection. Early detection helps you get treatment faster. Our testing service provides access to Quest Diagnostics locations nationwide. If you have symptoms of a kidney infection, getting tested quickly matters for your health.
Treatment options
- Antibiotics for 10 to 14 days, sometimes started through an IV in severe cases
- Pain relievers to reduce fever and discomfort
- Drinking plenty of water to help flush bacteria from the urinary tract
- Rest to help your body fight the infection
- Avoiding caffeine, alcohol, and spicy foods that irritate the bladder
- Urinating frequently and completely emptying your bladder
- Applying heating pads to the back or abdomen for pain relief
- Hospital admission for severe cases, pregnancy, or if you cannot take oral medications
- Follow-up urine cultures to confirm the infection has cleared
- Treating underlying conditions like kidney stones or diabetes
Concerned about Pyelonephritis? Get tested at Rite Aid.
- Simple blood draw at your nearest lab
- Results in days, not weeks
- Share results with your doctor
Frequently asked questions
A urinary tract infection or UTI is a general term for any infection in the urinary system. Pyelonephritis specifically refers to a kidney infection, which is more serious. Simple bladder infections cause mild symptoms and respond quickly to treatment. Pyelonephritis causes high fever, severe pain, and can damage kidneys if left untreated.
With proper antibiotic treatment, most people start feeling better within 2 to 3 days. You should take the full course of antibiotics, usually 10 to 14 days, even if symptoms improve. Complete recovery typically takes 1 to 2 weeks. Without treatment, the infection can worsen quickly and cause serious complications.
No, pyelonephritis will not go away without antibiotic treatment. This is a serious bacterial infection that requires medical care. Untreated kidney infections can spread to the bloodstream, causing sepsis. They can also lead to permanent kidney damage or kidney failure.
Pyelonephritis itself is not contagious from person to person. The bacteria that cause it usually come from your own digestive tract. However, bacteria can spread during sexual activity or poor hygiene practices. Good bathroom hygiene and safe sex practices help prevent infection.
Kidney infections cause different symptoms than simple bladder infections. You will likely have high fever, chills, and pain in your back or side. Nausea, vomiting, and feeling very sick are common. If you have a UTI and develop these symptoms, seek medical care immediately.
Doctors use urine tests to look for bacteria, white blood cells, and blood in your urine. A urine culture identifies which bacteria are present. Blood tests check for infection spreading beyond the kidneys. Imaging tests like ultrasound or CT scans may be ordered to look for complications.
Yes, several steps reduce your risk of repeat infections. Drink plenty of water throughout the day to flush bacteria. Urinate after sexual activity and wipe from front to back. Avoid holding urine for long periods and empty your bladder completely. Your doctor may prescribe low-dose antibiotics if you have frequent infections.
Some people can take oral antibiotics at home. You may need hospitalization if you have severe symptoms, cannot keep down medications, or are pregnant. People with weakened immune systems or other serious health conditions often require hospital care. Very high fever, severe pain, or signs of sepsis require emergency treatment.
Untreated or severe pyelonephritis can lead to serious problems. The infection may spread to the bloodstream, causing sepsis. Pus pockets called abscesses can form in the kidneys. Repeated infections may cause permanent kidney scarring and reduced kidney function.
Women are much more likely to develop kidney infections than men. Pregnant women, people with diabetes, and those with kidney stones face higher risk. Urinary catheter use, structural urinary tract problems, and weakened immune systems increase susceptibility. Older adults and young children are also at increased risk.