Hello, You should be seen by a doctor and appropriately worked up for potential cardiac or neurological disorders. You may also be suffering from metabolic disturbances having to do with electrolyte disturbances if you are running on the dehydrated side for some reason although you don t feel this should be a factor. You may also be taking medications that are overactivating your vascular tree and causing sudden vasodilation and syncope or loss of consciousness. I would advise that you find a friend or family member who can accompany you and DRIVE YOU to your primary doctor or Urgent Care Center for a check up and necessary testing. Hope I have answered your query. Let me know if I can assist you further. Take care Regards, Dr Dariush Saghafi, Neurologist