fluid balance
Regulation of the amount of liquid in the body. A negative fluid balance (fluid deficit) may occur when fluids are lost by vomiting, diarrhea, bleeding, or diaphoresis. Fluid overload may result from the excessive administration of intravenous fluids, or in diseases marked by impaired fluid excretion, such as congestive heart failure, cirrhosis, or kidney failure.
SEE: dehydration; diuresis; fluid replacement; and entries beginning with the words fluid volume.
Treatment of fluid imbalances depends on the cause; the patient's cardiac, renal, and hepatic function; measured serum electrolytes; and acid-base balance.
Useful means of gauging changes in fluid balance are 1) measurement of fluid inputs and outputs; or 2) measurement of day-to-day variations in body weight.