I am a physically fit, active 49-year-old female. I am 5'4", 123 lbs. For the past week or so, I have been having lightheadedness, fatigue, nausea (no vomiting) and some additional intenstinal rumblings (just noise like gurgling and 'movement' in my belly). No other particular symptoms. I run and work out several times a week. Although I have trouble getting motivated to exercise, once I get started, the exercise tends to improve how I feel. I am working out in an air-conditioned gym, so not heat stroke. I've always sweated profusely when I work out. I have had mild hypothyroidism, but am on natural supplements prescribed by my Ob/gyn. I am on no other medications, but take supplements including the thyroid supplement, a multi, fish oil, calcium, Ocuvite. I do not eat a lot, but haven't been for many years. I try to eat healthy foods like cheese, nuts, milk, fruit, some veggies, a little bit of meat a few times a week, carbs such as a tortillas. I also drink about 4-8 oz. of wine several evenings a week. I am definitely not pregnant, having had a partial hysterectomy 18 months ago.