I go to a pain clinic for 5-oxy-3.25 tylenol (Percoset). I take it at night. I do not know what this is, but it has plagued me for the past 8 years. I have autoimmune with fibro overlap. It is definitely affected by diet (stick to non-processed, low sugar, avoid inflammatory foods) and improved by movement during the day to strengthen and loosen tight tendons and muscles. I found that edema massage (toes to torso/fingers to shoulders) as on you tube, laying next to the wall with legs up against it for 20 minutes, basic cat/cow/child/cobra yoga, elevating legs and doing pumping (heel to toe) motions makes a difference. My D3 levels were low and so I take that and B vitamins. So: make sure you do move periodically throughout the day and stay hydrated; this is not something that you can improve with rest in bed.