The amount of urine your body produces in a day can be directly related to your health. The kidneys' main function is to maintain the correct balance of water and various chemicals in your blood. If your kidneys aren't functioning properly, an increase or decrease in urinary output could indicate the presence of kidney disease. As of 2013, kidney disease is the eighth leading cause of death in the U.S., according to the Centers for Disease Control and Prevention.
The kidneys remove waste products from your blood and expel them in your urine. They accomplish this by filtering your blood. Your kidneys reabsorb the molecules, nutrients and water your body needs and excrete concentrated waste products. When the kidneys aren't functioning properly, waste and fluid that are typically removed from your body in the urine can accumulate and cause disease.
Normal Urinary Output
The normal range for an adult urinary output is between 400 to 2,000 mL of urine daily -- with a normal fluid intake of about 2 liters per day. Values for normal urinary output may vary slightly between laboratories. A urine output of 500 mL per day is generally considered adequate for normal function.
Factors other than kidney disease that can influence how much you urinate in a day include how much water you consume, the amount of fluid lost in perspiration, your caffeine and alcohol intake and any medications you've taken. If your doctor is concerned about your kidneys, a 24-hour urine collection test is typically ordered.