Differential diagnosis and treatment of orthostatic intolerance: a narrative review

Purpose: Orthostatic intolerance is a common condition encountered in primary care and encompasses a range of symptoms triggered by standing. This review aims to provide general physicians with a practical framework for understanding terminology, diagnostic criteria, differential diagnosis, and management of orthostatic intolerance.Current concepts: Hemodynamic orthostatic dizziness/vertigo is defined by the International Classification of Vestibular Disorders as 5 or more episodes of dizziness, unsteadiness, or vertigo triggered by arising or present during the upright position, which improve with sitting or lying down, in the presence of documented orthostatic hypotension (OH), postural orthostatic tachycardia syndrome (POTS), or syncope. Measurement of orthostatic blood pressure and heart rate is essential for screening. The differential diagnosis includes benign paroxysmal positional vertigo, persistent postural-perceptual dizziness, anxiety disorders, bilateral vestibulopathy, primary orthostatic tremor, sensory neuropathy, gait disorders, and cardiac conditions. Evaluation of OH requires a stepwise approach to distinguish neurogenic from non-neurogenic causes. Evaluation of POTS focuses on identifying pathophysiological subtypes, including neuropathic, hyperadrenergic, deconditioning-related, and hypovolemic forms.Discussion and conclusion: Management begins with nonpharmacological strategies, including adequate hydration, increased salt intake, use of compression garments, postural education, and adjustment of contributing medications. When these measures are insufficient, pharmacological treatments for OH include midodrine, droxidopa, fludrocortisone, and pyridostigmine, whereas POTS may be managed with low-dose beta-blockers, ivabradine, or midodrine. A systematic approach incorporating appropriate terminology, standardized diagnostic criteria, and stepwise management is essential for optimizing care in patients with orthostatic intolerance.