A kidney infection originates from the bladder (cystitis) or the urethra (urethritis). The bacteria can travel through the ureter, which is what connects the kidney to the bladder, and infect the organ. The Inflammation of the kidney due to a bacterial infection is called pyelonephritis.
How long it takes for the cystitis or urethritis to develop into a kidney infection depends on the bacteria, the strength of the immune system of the patient and other factors, Dr. Prince Mohan, M.D., medical director of transplant nephrology, Geisinger Health System, says.
If the infection in the bladder or urethra is treated in time, the bacteria should not go up to the kidneys; but if ignored for 2-3 days or more and the patient has a fever, the microbes probably ended up in the kidney resulting in pyelonephritis, Dr. Mohan adds. Severe kidney infection can lead to life-threatening complications.
Having a double collecting system, when the kidney has two ureters carrying urine from the kidney to the bladder, does not cause infections as often as people may think, Dr. Mohan says. The problem is vesicular urethral reflux – when an obstruction in the bladder or urethra causes urine to flow backward into the kidneys. “But this is not very common at all,” he adds.
A risk factor that is not often mentioned is recent sexual intercourse, Dr. Mohan says. That’s why urinary tract infections’ nickname is “honeymoon cystitis.” Good hygiene habits and proper cleaning techniques, such as “front to back” are very important, he adds.
One in three people who get a kidney infection will have some sort of urethritis signs as well, Dr. Mohan says. The treatment in either case remains antibiotics. The biggest risk factor is being a woman because a woman’s urethra is closer to the vagina and anus where bacteria live. That makes it quicker and easier for the microbes to infiltrate the bladder.
UTIs should be treated appropriately, Dr. Mohan says. “Excessive use of antibiotics can lead to resistance.” People should go to their primary physician for a urine check. If nothing is found in it, antibiotics should not be given, he adds.