What are the initial signs of a kidney infection?

Initial signs of a kidney infection include abdominal discomfort, urinary frequency and burning upon urination, explains Mayo Clinic. Infected individuals may also suffer from back pain and notice blood or pus in their urine.

Symptoms that commonly develop as kidney infections progress include flank pain, queasiness, fever and vomiting, according to WebMD. The urine may also appear cloudy and emit a strong, unpleasant odor. Kidney infections often occur when bacteria that develops in the bladder during a urinary tract infection makes its way into the kidneys. The bacteria can also spread into the blood and cause serious illness. In most cases, antibiotic treatment cures kidney infections.