Pyelonephritis is a sudden and severe kidney infection which causes the inflammation of kidneys and may permanently damage them. It may be life threatening. It is a bacterial infection of the kidneys where in most of the cases it can be cured without causing long lasting renal damage. It can be severe and is usually quite painful and few patients need to be hospitalized. In acute pyelonephritis small dot like structures can be found which are called as “ABSCESSES”. Complicated pyelonephritis includes pregnant patients, patients with uncontrolled diabetes, kidney transplants, urinary anatomical abnormalities, acute or chronic kidney failure, as well as immunocompromised patients and those with hospital-acquired bacterial infections. It is a Life-threatening kidney disease which destroys the skin muscle tissue leading to the renal infection which is characterized by the production of gas in kidneys. The goal of treatment is to control the infection and reduce the symptoms usually resolve within 48-72 hours after appropriate treatment. Oral or IV Fluids, antipyretics, pain medications and a dose of parenteral antibiotics are generally referred as the treatment for pyelonephritis. Antibiotics are the first line therapy for pyelonephritis. The antibiotics are generally given for 14 days but the patients who are receiving Fluoroquinolone and Ciprofloxacin the treatment can be shortened to 7 days. Although the drugs can cure the infection within 2-3 days nut the medication must be taken for entire 14 days.