A nurse calculates net fluid balance as intake minus output; what does a negative net balance indicate?

• A. Positive balance
• B. Negative balance
• C. No change
• D. Excessively high intake

Answer: (A)

Net fluid balance shows whether a person is gaining or losing fluid by subtracting outputs from inputs. When the result is negative, more fluid is leaving the body than entering, creating a fluid deficit. This indicates dehydration or hypovolemia and prompts attention to increasing intake or reducing losses (for example, addressing vomiting, diarrhea, sweating, or inadequate oral intake). Clinically, watch for signs such as dry mucous membranes, tachycardia, orthostatic hypotension, and reduced skin turgor. In contrast, a positive balance means fluid is accumulating, while a zero balance means fluid status is stable.