Ceiling cracks and floorboard issues

[Elsiebear1]

I live in a house approx 25 years old. There are no issues at all with the outside or brickwork. However I have noticed hairline cracks in the paint of most ceilings both upstairs and down that have only appeared in the last year. Also the wooden floorboards upstairs have started to creak a lot more and also raise up in some areas, I have lifted the carpets and can see no problems at all.
What could be the cause of these issues and is it just the house ageing slightly now or is it something to worry about

Any help would be very much appreciated to put my mind at rest

Thanks

Creaking floorboards is nothing to worry about, its what they do.
I'm not an expert but if the cracks are horizontal, or running between the walls and ceiling then it's just where the house is settling, which can take a number of years. Just have to keep an eye on them. Vertical cracks, and certainly external ones would need looking at.
At 25 years old my guess would be cheaply built modern build. But I am a bit biased on that front based on past experience.