BP question for OT Docs

My father 80 years old, self employed, still works nearly full time. Nonsmoker, occasional light drinker.

Chronic arthritis which causes him a good deal of pain, mild Type II diabetes, well controlled on the lowest dose of metformin. Has had hypertension since his forties, has been under control in the normal range since then. I don't know what he takes, but he's always had the same medication and dosage since he started taking it years ago. No recent lifestyle or medication changes.

For about a week, he's been waking up in the morning with BP around 150/90. It drops a little bit after his daily walk on the treadmill. His Dr just said monitor it for another week or 10 days.

How concerned would you be if a patient presented with this, and what would you recommend? I realized that's not a super high number for someone his age, but the sudden change is worrisome to me.

TIA, and Sofia thanks you too

Edit: sofia removed per admin request