About 3 times a year my husband has spells of sudden profuse sweating, nausea , vomitting and general weekness and fatigue . The sweating spells last for about 12 hours. He has chills and restlessness. He is diabetic and it is not his blood sugars. Blood pressure drops low for 2 to 3 days afterward. Has a pacemaker and has had it checked. his heart checks out ok when he goes to er and no one knows what is causing it