Kidney infections are treated with antibiotics, and most people can recover at home with an oral prescription lasting 5 to 14 days. The specific antibiotic, dose, and duration depend on the bacteria causing the infection and how severe your symptoms are. Some cases require a hospital stay for intravenous antibiotics, but the majority of uncomplicated kidney infections clear up with pills alone.
Antibiotics Are the Primary Treatment
A kidney infection (pyelonephritis) is a bacterial infection, and antibiotics are the only reliable way to clear it. The bacterium responsible in most cases is E. coli, the same one behind most bladder infections. Your doctor will typically start you on antibiotics right away, often before your urine culture results come back, because waiting days for lab confirmation risks letting the infection worsen.
The most commonly prescribed first-line options are fluoroquinolone antibiotics like ciprofloxacin or levofloxacin. These are effective against the bacteria that cause most kidney infections. However, antibiotic resistance is a growing concern. If fluoroquinolone resistance rates in your area exceed 10%, your doctor may choose a different antibiotic or give you a one-time injection before switching to oral pills. Another antibiotic, trimethoprim-sulfamethoxazole (sold as Bactrim or Septra), is not recommended as a first choice for kidney infections because E. coli resistance rates are too high. It can be used if lab results confirm the bacteria in your urine are susceptible to it.
This is why urine cultures matter. Your doctor collects a urine sample at your first visit and sends it to a lab. If the initial antibiotic isn’t working, the culture results (usually available in two to three days) guide the switch to one that will.
How Long You’ll Take Antibiotics
Treatment courses have gotten shorter over the years. Updated 2025 guidelines from the Infectious Diseases Society of America recommend 5 to 7 days of a fluoroquinolone antibiotic for most people with kidney infections who are improving on treatment. If you’re taking a non-fluoroquinolone antibiotic, a 7-day course is the current recommendation. Older protocols called for 10 to 14 days, and some doctors still prescribe longer courses depending on the situation.
Men with a kidney infection where prostate involvement is suspected may need 10 to 14 days, though the optimal duration for this group isn’t well established. People with complicated infections, structural abnormalities in the urinary tract, or weakened immune systems also tend to get longer courses.
Finishing the full course matters even if you start feeling better within a day or two. Stopping early can leave surviving bacteria behind, which raises the risk of the infection coming back or becoming resistant to that antibiotic.
When Hospital Treatment Is Needed
Most kidney infections are treated entirely at home, but certain situations call for hospital care with intravenous antibiotics. You’re more likely to need hospitalization if you can’t keep fluids or oral medication down due to severe nausea and vomiting, if you have a high fever with signs of sepsis (such as rapid heart rate, confusion, or very low blood pressure), or if you’re pregnant.
People with diabetes, a single kidney, a kidney transplant, or a known obstruction like a kidney stone blocking urine flow are also at higher risk for complications. In the hospital, IV antibiotics bring drug levels up quickly, and once symptoms start improving, doctors typically switch you to oral antibiotics to finish the course at home.
What to Expect During Recovery
Fever and chills are usually the first symptoms to improve, often within 24 to 48 hours of starting antibiotics. Flank pain and the general feeling of being unwell take a bit longer, typically easing over two to four days. If your fever hasn’t broken after 48 to 72 hours on antibiotics, that’s a sign the medication may not be effective against your particular bacteria, and your doctor will likely adjust treatment based on culture results.
During recovery, drinking plenty of water helps flush bacteria from the urinary tract and keeps you hydrated, especially if you’ve had a fever. Rest is important in the first few days. Avoid alcohol, which can interact with some antibiotics and contribute to dehydration. Most people feel significantly better within a week and are fully recovered by the time they finish their antibiotic course.
Supplements and Home Remedies
No supplement or home remedy can replace antibiotics for an active kidney infection. This is worth stating clearly because cranberry products, D-mannose, and similar options are widely marketed for urinary health, and it’s tempting to try them when you’re in pain.
The evidence for cranberry extract and D-mannose is primarily in prevention, not treatment. A combination of cranberry extract and D-mannose can block E. coli from attaching to the bladder wall, and studies show D-mannose is as effective as antibiotics at preventing recurrent urinary tract infections. One clinical trial found that adding cranberry extract plus D-mannose to standard antibiotic therapy resulted in a lower recurrence rate (about 4%) compared to antibiotics alone, and may increase bacterial sensitivity to the antibiotic. But preventing a future infection and treating a current kidney infection are very different things. A kidney infection left to antibacterial supplements alone can progress to a bloodstream infection.
If you get recurrent UTIs that escalate to kidney infections, these supplements are worth discussing with your doctor as a preventive strategy between episodes. During the active infection, stick with your prescribed antibiotics.
Preventing Another Kidney Infection
Kidney infections almost always start as bladder infections that travel upward through the ureters. Reducing your risk of bladder infections is the most effective way to avoid another kidney infection. Staying well hydrated, urinating after sex, and wiping front to back all reduce the chance of bacteria entering the urinary tract. If you experience burning or urgency that suggests a bladder infection, getting treated promptly keeps it from reaching the kidneys.
For people who get three or more UTIs per year, preventive options include low-dose daily antibiotics, post-sex antibiotics, or the cranberry and D-mannose supplements described above. Your doctor can help decide which approach fits your pattern of infections.