Hi @smoothiesuzy I was surprised to read your post as I have been having the same issue of waking nearly every night sometime in the window of between 2AM and 5AM with a sensations of "nervousness" or what I've described as "butterflies in stomach" and a shaky/fearful sensation. I have had sooooooo many tests as this has gone on for over a decade now. The onset occurred at the time of a very litigious divorce, and was diagnosed as anxiety which made perfect sense at the time. However, it has continued relentlessly through the years even though I am happily re-married and have a relatively stress-free (but active and busy) life. What struck me about your post is that I too have been diagnosed with reactive hypoglycemia and POTS in addition to having a history of palpitations and occasional episodes of SVT arrhythmia . I also have a history of hormonal migraines but those are subsiding as I am entering menopause. I live in the Los Angeles area and recently consulted with a premier endocrinologist who told me it was entirely attributable to menopause and my dropping estrogen level. I would love to finally have a diagnosis, but am a bit skeptical that it is entirely menopause causing these nightly episodes as they started so long ago (I believe about 2006) and my cycles only became irregular last year. I have been wearing a "freestyle libra" glucose monitor for nearly 2 months that initially showed my glucose dropping below 50 nightly between 2-6 in the morning. I was so excited thinking we'd solved the mystery. I made sure to have a snack before bed and keep a snack next to my bed if needed and successfully have kept my blood glucose from dipping....and yet....the nightly wake up of "stage fright" or butterflies in stomach" continues even with perfect glucose levels. I have had thyroid tests as well as rheumatology and endocrinology labs galore, but so far no one has been able to explain my nightly episodes. My GP is thinking it is a blood pressure issue as I am petite and thin, and female and generally run very low. I started tracking my BP with a device that sends a recored to my phone. (It's been wonderful having measurable results from the freestyle libra glucose monitor and bluetooth blood pressure monitor to show doctors and I highly recommend these items to anyone needing to show their doctor what is happening) My BP is consistency low usually 100/60 but diastolic can even dip into the 40's at times. The premier LA endocrinologist said this is not related to my nightly episodes and simply normal BP for me. He may be right because measuring my BP when I awake with an episode of nervousness/shaking my BP is typical and pulse is on higher end but nothing crazy. My history of palpitations and SVT was being managed for the past two years by taking 12.5 mg of atenolol, but I recently stopped taking due to concerns about it affecting glucose and BP and I am doing fine without it. I am currently not taking any prescriptions meds, staying away from any caffeine (as my heart is very sensitive to it) , and just taking a few basic supplements. Please post more if you find a cause for your "middle of the night episodes" or any other related info. I would really appreciate it. Thanks so much!