Chronic constitutional hypotension

Constitutional hypotension (CHT) is defined as a systolic blood pressure below 105 mmHg in an adult woman and below 110 mmHg in an adult man. Although the general medical community considered individuals with CHT as having an optimal phenotype of blood pressure, many subjects with CHT report a myriad of psychosomatic symptoms, which affect their quality of life. The frequently reported syncope and orthostatic intolerance symptoms in individuals with CHT could be related to a perturbation in cardiovascular autonomic control. Uncertainty and paucity of data exist on the (patho)-physiology of this low blood pressure phenotype, which has been neglected by medical investigators. In this chapter, we will report our clinical observations and those of others on pathophysiology of CHT and compare them with equivalent findings on individuals with a high normal blood pressure phenotype.