Causes of Syncope

Reflex (neurally mediated) syncope: This includes Vasovagal (mediated by orthostatic or emotional stress), situational (e.g. cough, sneeze, micturition, post-exercise, post-prandial), Carotid sinus, etc.
Orthostatic syncope: Primary autonomic (pure autonomic, Parkinson’s, Lewy body dementia), Secondary autonomic (Diabetes, amyloidosis, uremia, spinal cord injuries), Drug-induced (alcohol, diuretics, vasodilators, antidepressants, phenothiazines), Volume depletion (Hemorrhage, diarrhea, Vomiting)
Cardiac Syncope: 1) Dysrhythmias – Bradycardia (AV block, tachy-brady syndrome) or Tachycardia (SVT, V-tach), 2) Structural Heart Disease (Valvular, ischemia, cardiomyopathy, tamponade, PE, aortic stenosis, pulmonary HTN)