A kidney infection requires antibiotics, and the sooner you start them, the better. Unlike a simple bladder infection that sometimes resolves on its own, a kidney infection (also called pyelonephritis) can become dangerous without treatment. Most people recover at home with oral antibiotics and supportive care, but about 11% of patients hospitalized for urinary tract infections develop septic shock, so recognizing when symptoms are serious is just as important as knowing how to manage mild ones.
Antibiotics Are the Primary Treatment
There is no home remedy or over-the-counter option that can clear a kidney infection. Bacteria have traveled up from the bladder into the kidney tissue, and only prescription antibiotics can eliminate them. Your doctor will typically start you on an antibiotic right away, sometimes before your urine culture results come back, then adjust if needed once they know the exact bacteria involved.
Most uncomplicated kidney infections are treated with a course of oral antibiotics lasting 7 to 14 days. Symptoms often begin to improve within a few days of starting treatment, but finishing the entire course matters. Stopping early can leave bacteria behind, making the infection harder to treat the second time around.
Managing Pain and Fever at Home
Kidney infections typically cause a dull, persistent ache in your back or side, often paired with high fever, chills, nausea, and painful urination. While antibiotics address the underlying cause, you still need to manage the discomfort in the meantime.
Acetaminophen (Tylenol) is generally considered safe for your kidneys at recommended doses and works well for both pain and fever. Be careful with combination products like cold medicines, which often contain acetaminophen as a hidden ingredient, making it easy to accidentally take too much. Anti-inflammatory painkillers like ibuprofen can be harder on the kidneys, so check with your provider before reaching for those, especially while your kidneys are already under stress from the infection.
A heating pad on your back or side can also take the edge off flank pain without adding any medication into the mix.
Hydration During Recovery
Drinking plenty of fluids helps your body flush bacteria from the urinary tract and supports kidney function while you heal. A reasonable target for most adults is 2.5 to 3.5 liters of total fluid per day, which works out to roughly 10 to 15 cups. A practical way to gauge whether you’re drinking enough: your urine should be pale yellow or nearly clear, and you should be urinating at least five to seven times per day.
If nausea or vomiting makes it hard to keep fluids down, that’s a red flag. Persistent nausea limits both hydration and your ability to take oral antibiotics, which may mean you need IV fluids and medication instead.
When a Kidney Infection Needs Hospital Care
Not every kidney infection can be managed at home. You may need to be admitted for intravenous antibiotics and fluids if you have:
- High fever that won’t break or signs of sepsis like rapid heart rate, confusion, or very low blood pressure
- Persistent vomiting that prevents you from keeping down pills or water
- Severe or hard-to-control pain that doesn’t respond to over-the-counter options
- No improvement after a few days of outpatient antibiotic treatment
People who are immunocompromised, have poorly controlled diabetes, have had a kidney transplant, or are suspected of having a urinary blockage (such as a kidney stone obstructing the ureter) are also more likely to need inpatient care. These conditions make it harder for the body to fight the infection and raise the risk of serious complications like bloodstream infection or kidney damage.
Kidney Infections During Pregnancy
Pregnancy changes the equation significantly. A kidney infection during pregnancy is linked to higher rates of preterm delivery, low birth weight, and serious maternal complications including sepsis. For this reason, pregnant individuals with pyelonephritis are typically admitted to the hospital rather than treated at home.
Antibiotic choices also narrow during pregnancy. Certain drug classes are considered safe, but the specific options depend on your trimester and the bacteria causing the infection. Notably, some commonly used UTI antibiotics can’t reach adequate levels in kidney tissue, so they work for bladder infections but not kidney infections. Your care team will choose an antibiotic that treats the kidney effectively while remaining safe for the pregnancy.
What to Expect During Recovery
Most people start feeling noticeably better within two to three days of starting antibiotics. Fever usually drops first, followed by gradual improvement in back pain and urinary symptoms. Full recovery generally takes one to two weeks, though fatigue can linger a bit longer.
During this time, rest matters. Your body is fighting a significant infection, and pushing yourself too hard can slow recovery. Stay on top of your fluids, take your antibiotics on schedule, and don’t be alarmed if you still feel run down for several days even after the worst symptoms pass.
If your symptoms return after finishing antibiotics, or if they never fully improve, contact your provider. You may need a different antibiotic, imaging to check for a structural problem like a kidney stone, or further evaluation.
Preventing Future Kidney Infections
Kidney infections almost always start as lower urinary tract infections that climb upward, so prevention focuses on keeping bladder infections from occurring or catching them early.
Basic habits that lower your risk:
- Drink at least 2 liters of fluid daily to keep urine flowing regularly
- Urinate every 4 hours during the day, even if you don’t feel a strong urge
- Wipe front to back to keep intestinal bacteria away from the urethra
- Urinate soon after sex, which helps clear bacteria that may have been introduced
- Avoid tight clothing like pantyhose or tight pants for prolonged periods, as moisture and warmth promote bacterial growth
For people who get recurrent UTIs, there are additional options. Cranberry products are sometimes recommended, though the American Urological Association notes their effectiveness is uncertain. D-mannose, a natural sugar supplement taken twice daily, has shown some promise in preventing recurrence. For postmenopausal women, topical vaginal estrogen can help restore the protective bacterial environment that declines after menopause, reducing UTI frequency.
If infections keep coming back despite lifestyle changes, your provider may recommend a low-dose antibiotic taken daily or after sex as a preventive measure. These regimens typically last at least six months and require consistent follow-through, but they can significantly reduce the number of infections in people who are prone to them.