Stress pain illness can all raise BG some people get BG rise before they know they are sick.
Hi. Diabetes can be a progressive condition, so it may worsen over time, even with your best efforts.
Another thing that may affect BG levels is illness / infection - even mild ones. For example an oral infection, fighting off the flu.
You can try increasing physical activity / reducing carbs, which may help. If levels still remain elevated, you may wish to discuss treatment options with your Dr.