Kidney infection, also known as renal infection or pyelonephritis, is a common type of urinary tract infection that occurs when bacteria enters the urinary tract through the tube (urethra) that carries urine from the body and can multiply and travel to the kidneys. If the kidneys, ureters, bladder, or urethra get germs in it, a UTI develops. Most often, the bladder gets infected first. This can be painful but isn’t usually serious. If the bad bacteria or viruses travel up the ureters, a kidney infection is the result. If left untreated, a kidney infection can cause life-threatening problems. Symptoms of a kidney infection include: blood or pus in the urine; fever and chills; loss of appetite; pain in the lower back, side, or groin; upset stomach or vomiting; and/or weakness or fatigue. If you would like to find out more and receive a second opinion regarding your diagnosis and treatment, please contact us at secondopinions.com, for your peace of mind.