Normal renal function or acute renal failure is a sudden or acute deterioration of kidney function due to injury by any insult. This leads to build up of waste products as well as electrolyte imbalance in body. Decreased GFR and increased creatinine is an indication seen in lab tests. It presents as decreased urine output (oliguria) or anuria (no urine output), edema in lower limbs and periorbital, fatigue, shortness of breath, pulmonary edema, confusion, uremic encephalopathy or seizures. Insults that can lead to acute kidney injury include: 1) decreased blood flow (hypotension, shock, bleeding, heart attack, liver failure, allergic reactions, burns or post-surgery) ,2) direct kidney damage (sepsis, multiple myeloma, vasculitis, interstitial nephritis, scleroderma) 3) urinary tract blockage (tumors, kidney stones, blood clots, urinary tract infections and nervous system problems). Acute kidney injury is tested by urine output monitoring, blood tests, GFR calculation and renal function tests.