An older client reports experiencing frequent dizzy spells. To assess for orthostatic hypotension, which action should the nurse take first?

A. Assist client to a supine position: The initial step in assessing orthostatic hypotension is to have the client lie supine for several minutes. This allows baseline blood pressure and heart rate to be measured in a stable, resting position before changing posture. B. Instruct the client to stand upright: Standing too soon without establishing baseline measurements may place the client at risk for falls or injury due to dizziness or sudden blood pressure changes. C. Place the client in a semi-Fowler's position: A semi-Fowler’s position is partially upright, which does not provide an accurate baseline for assessing orthostatic changes compared to the supine position. D. Help the client sit on the side of the bed: Sitting at the bedside is part of the assessment sequence, but it should occur after obtaining supine baseline readings to safely monitor changes in blood pressure and heart rate.