Vasovagal syncope ("the common faint") and near syncope from initial orthostatic hypotension are huge medical problems given the number of patients and their impact on quality of life. The treatment options are often unsatisfactory. The studies in this thesis set out to investigate the potential benefits of physical counter-manoeuvres in the acute management of vasovagal syncope and initial orthostatic hypotension. Once shown to be effective, further studies elucidated how they work.