Orthostatic challenge produced by upright posture may lead to syncope if the cardiovascular
system is unable to maintain adequate brain perfusion. This review outlines orthostatic
intolerance related to the aging process, long-term bedrest confinement, drugs, and disease.
Aging-associated illness or injury due to falls often leads to hospitalization. Older patients
spend up to 83% of hospital admission lying in bed and thus the consequences of bedrest
confinement such as physiological deconditioning, functional decline, and orthostatic …