Question: What is (are) Pyelonephritis: Kidney Infection ?
Answer: The urinary tract is the bodys drainage system for removing wastes and extra water. The urinary tract includes two kidneys, two ureters, a bladder, and a urethra. The kidneys are two bean-shaped organs, each about the size of a fist. They are located near the middle of the back, just below the rib cage, one on each side of the spine. Every day, the two kidneys process about 200 quarts of blood to produce about 1 to 2 quarts of urine, composed of wastes and extra water. Children produce less urine than adults. The amount produced depends on their age. The urine flows from the kidneys to the bladder through tubes called the ureters. The bladder stores urine until releasing it through urination. When the bladder empties, urine flows out of the body through a tube called the urethra at the bottom of the bladder.
Source: NIDDK

Question: What causes Pyelonephritis: Kidney Infection ?
Answer: Pyelonephritis is caused by a bacterium or virus infecting the kidneys. Though many bacteria and viruses can cause pyelonephritis, the bacterium Escherichia coli is often the cause. Bacteria and viruses can move to the kidneys from the bladder or can be carried through the bloodstream from other parts of the body. A UTI in the bladder that does not move to the kidneys is called cystitis.
Source: NIDDK

Question: What are the symptoms of Pyelonephritis: Kidney Infection ?
Answer: Symptoms of pyelonephritis can vary depending on a persons age and may include the following: - fever - vomiting - back, side, and groin pain - chills - nausea - frequent, painful urination Children younger than 2 years old may only have a high fever without symptoms related to the urinary tract. Older people may not have any symptoms related to the urinary tract either; instead, they may exhibit confusion, disordered speech, or hallucinations.
Source: NIDDK