Hi, I want to know- 1) Your age, gender. 2) Presence of diabetes, high blood pressure, cholesterol problems and treatment for it if any. 3) Habits like smoking, alcohol. 4) Presence of mental stress if any. 5) Whether you can sleep well till the start of symptoms. 6) Any associated chest pain, breathing difficulties on minor exertion. As you have to wake up from sleep at night you should not neglect it. There might be following causes 1) Anxiety: if you are not able to sleep in night due to any mental stress (you have mentioned as few things in mind ) anxiety is more likely. 2) Hypoglycemia (Low blood sugar level) this may happen in patients with diabetes on insulin treatment (particularly with intermediate acting insulin). 3) Heart problem (Cardiac arrhythmia or heart attack): if associated with chest pain (though in diabetic patient chest pain may be absent). So I will advise you to consult cardiologist and get done clinical examination. Following investigations may help in excluding heart problems: 1) ECG. 2) 2DEcho of heart. 3) Electrophysiological study of heart, Holter s monitoring. 4) Blood tests for cardiac enzymes like CPK-MB, Troponin I/T. 5) Stress test. If you are not a diabetic and all above tests are normal then try relaxation techniques and consult psychiatrist.