Snapshot A 66-year-old man presents to his primary care physician for generalized weakness and episodes of lightheadedness. He says that his symptoms began approximately a few weeks ago after there was a change in his blood pressure medications. Medical history is significant for hypertension and newly diagnosed benign prostatic hyperplasia. After being in the supine position for 5 minutes, he was asked to stand, and a blood pressure was obtained 3 minutes after standing. There was a 23 mmHg decrease in systolic blood pressure. Introduction Clinical definition a decrease in blood pressure while the patient is standing compared to when they are sitting or in a supine position ≥ 20 mmHg decrease in systolic blood pressure OR ≥ 10 mmHg decrease in diastolic blood pressure Epidemiology Incidence commonly seen in the elderly likely secondary to impaired baroreceptor sensitivity Risk factors antihypertensive medications diuretics volume depletion (e.g., vomiting and hemorrhage) Etiology Autonomic failure Volume depletion/dehydration most common cause in the elderly while not necessary for diagnosis, may show decreased FENa (<1%) Medications (e.g., terazosin) Pathophysiology physiology gravitational pooling of blood decreases venous return, cardiac output, and blood pressure compensatory mechanisms regulate blood pressure by controlling vasoconstriction heart rate cardiac contractility pathogenesis failure of compensatory mechanisms to regulate blood pressure when the patient is in the upright position e.g., autonomic failure Presentation Symptoms dizziness lightheadedness vision changes (e.g., vision blurring or darkening) generalized weakness Studies Blood pressure measurements obtain blood pressure measurements 2-5 minutes after the patient is standing from a supine position it is diagnosed if there is ≥ 20 mmHg decrease in systolic blood pressure OR ≥ 10 mmHg decrease in diastolic blood pressure Electrocardiogram performed to rule-out cardiac arrhythmia Treatment Conservative treat the underlying cause e.g., medication alterations dietary modification in the absence of hypertension, the patient should increase fluid and salt intake Medical midodrine or fludrocortisone indication indicated in patients who do not respond to conservative treatment Complications There is an increased cardiovascular and all-cause mortality