Why do I wake from sleep with pounding heart, SOB, and chest tightness. This is a recent occurrence. I am a 66 yrs old, female in good health. Only negative is overweight , but not morbidly obese. Take 10 mg of Lipitor for cholesterol , but have had no high blood pressure, and my fasting blood sugar is below 90. I take one .100 mcg tablet daily for a thyroid condition.