neurons are also affected. 7,8 Autonomic dysfunction in synucleinopathies occurs at all stages of the disease and occasionally is its only manifestation. 9Among the most debilitating manifestations of autonomic dysfunction in PD is orthostatic hypotension (OH), which is a sustained fall in blood pressure (BP) on standing. The current definition of OH, based on expert consensus, 10 is a fall of at least 20 mmHg in systolic BP or 10 mmHg in diastolic BP within 3 minutes of standing or upright tilt. OH can impair perfusion to organs above the heart, most notably the brain, resulting in symptoms of tissue hypoperfusion. Symptoms can be very disabling, have a profound impact on a patient's quality of life, and increase morbidity and mortality. 11,12 In PD and other synucleinopathies, OH is neurogenic (nOH), i.e., due to reduced norepinephrine release from postganglionic efferent sympathetic nerves, resulting in defective vasoconstriction when assuming the upright posture (Figure 1). 10 Complicating nOH management is arterial hypertension when supine (SH), which occurs in up to 50% of patients with efferent baroreflex failure. 13,14 When recognized, nOH can be treated, sometimes successfully. Discontinuation of potentially causative/aggravating drugs, patient education, non-pharmacological approaches, and pathophysiology-based drug therapy are key to an effective management.Here we review the epidemiology, evaluation, and management of nOH, with emphasis on patients with PD, summarize the non-pharmacologic and pharmacologic treatment strategies, and provide practical advice on the management of patients with this debilitating condition.