Which of the following is a sign of orthostatic intolerance or dehydration due to diuretics that should be reported?

• A. Increased energy
• B. Frequent headaches
• C. Dizziness on standing
• D. Dry mouth

Answer: (C)

Standing up requires the body to quickly adjust blood pressure to keep brain blood flow adequate. Diuretics lower overall blood volume, so this adjustment can falter, leading to orthostatic intolerance. The clearest sign of that problem is dizziness or lightheadedness when you stand, which indicates reduced blood flow to the brain and should be reported to a clinician. Dry mouth and headaches can occur with dehydration, but they don’t specifically point to the orthostatic change that happens on standing. Increased energy would not be expected with dehydration or orthostatic intolerance. If dizziness on standing occurs, it may mean the diuretic dose needs review or hydration status needs evaluation.