Walls and Ceilings - Cracks in the tile grouting

I just noticed a lot of cracks in my bathroom tile grouting. The cracks run from the floor to the ceiling in the corners. I just moved into the house in May. There are also cracks along the window and the floor where it meets the walls. I also have cracks around the doorway. What would be causing these cracks. Is this a major problem. Is my house going to fall apart. The house is 50+ yrs. Before we moved in it went through a total renovation. Please Help

I don't think anyone can give you a real accurate assesment based on what you have said. There are a number of possibilities (foundation related) but I would suggest that you get a structural engineer to inspect your home. Soon.

You need to caulk,not grout, those spots where 2 surfaces[similar or not] join at a corner. Take out what is there and caulk it.

JoneQ is correct. Intersecting corners should be caulked rather than grouted. Sounds as if your previous installer went the easy route by grouting the entire area. What you're describing is typical of those areas and probably (not for sure) not a sign of serious foundation/structural issues. Remove the grout (not a fun job) - caulk the seams... and monitor for further movement - at which point it is time to worry about a structural problem.

I like the capital Q. I may adopt it ;)