There's a lot of good advice in this thread! Here's my input:
Get a lot of datapoints at different times of day and it'll give you a much better idea of where you're at. There isn't a concrete target blood pressure for ADHD meds per-se but ideally your baseline should be less than what qualifies for hypertension. Note that the body takes some time to adjust to ADHD meds and blood pressure levels in the first week or so are going to be significantly higher than they will be after a couple weeks on the medication. In terms of potential lifestyle changes, on top of lowering caffeine intake making daily walks into a habit can do wonders for blood pressure.
Any information about what communication they were referencing here?