Cracks in wall: Is this serious?

[LinPur]

Hello! Based on these images, is it possible to say anything about what these cracks might be due to? I have very little knowledge myself. Grateful for any help!

 

[klaskarlsson]

Hi! Based on these pictures, is it possible to say anything about what these cracks might be due to? I have very little knowledge myself. Grateful for any help!

Settling of the house or vibrations?
Or if it has been plastered incorrectly and more or less directly or over time cracked (perhaps less likely).

IF you fill + paint: will they come back?
Are there other indications that the house has settled or if something is ongoing?

 

[LinPur]

Thanks for the response!
There are minor cracks in other places in the house, but I have now found out that the house is built on bedrock, so that feels a bit more reassuring. I was worried that the whole house was sinking or something similar. I will keep an eye on the cracks over time to ensure they don't worsen. Is there anything else that would be good to keep in mind?