causing or capable of causing death; mortal; deadly: a fatal accident; a fatal dose of poison. causing destruction, misfortune, ruin, or failure: The withdrawal of funds was fatal to the project. decisively important; fateful: The fatal day finally arrived.
Extreme cold spells may come. Submitted by Erika (not verified) on Mon, 2009-09-28 13:40. Extreme cold spells may come from bad circulation (the blood not flowing properly) or from the thyroid (low thyroid function leads to a lower body temperature).
Heavy menstrual bleeding also can cause this type of lightheadedness. Sometimes the cause of lightheadedness is an abnormal heart rhythm , which can cause fainting spells (syncope). Unexplained fainting spells need to be evaluated by a doctor. You can check your heart rate by taking your pulse. Many prescription and nonprescription medicines can cause lightheadedness or vertigo. The degree of lightheadedness or vertigo that a medicine causes will vary.