Hello - I also can have unexplained high readings during the day... and then sudden drops and hypos during the night. Things got better when I read the book Think Like a Pancreas and got a better undertsanding about what causes increased blood sugar because (this surprised me) it's not just eating carbs! So here are the things which give me a spike: any sort of social interaction; any sort of stressful situation (including just a challenging meeting, giving a presentation, or thinking I might miss the train); anerobic exercise (I'm not a gym bunny but volunteer at a local charity shop and lifting/moving donation bags does it). Sometimes a spike comes as a natural 'bounce' after going low (not hypo). Does any of this sound familiar?