Review symptoms such as rapid heartbeat on standing, dizziness, lightheadedness, fainting, fatigue, brain fog, palpitations, nausea, and exercise intolerance
Measure heart rate and blood pressure after lying down for several minutes and again after standing
Look for a sustained increase in heart rate of at least 30 beats per minute within 10 minutes of standing in adults, or at least 40 beats per minute in adolescents
Check for absence of significant orthostatic hypotension
Perform an active stand test in a clinic or at home under medical guidance
Perform a tilt table test if needed
Review medical history, medications, fluid intake, recent illness, and triggers
Rule out other causes such as dehydration, anemia, thyroid disease, infection, heart rhythm problems, and anxiety disorders
Order blood tests when appropriate, including complete blood count, thyroid function, electrolytes, and iron studies
Consider electrocardiogram and other cardiac testing if symptoms suggest a heart condition
Refer to a cardiologist, neurologist, or autonomic specialist for confirmation if needed