Does a crack start from the bottom up or the top down on a wall

You need to give more info, ie wheres the crack, ground floor, 1st floor, inside wall, outer wall, in a corner. We dont sit here with a crystal ball.

LOL!..........I've seen it all now. What difference does it make? Surely your question and concerns should be WHY my walls have cracks in them,what could be the cause of them and how to rectify them!

it depends it can go either way, if it is subsidence it can start at the bottom, but sometimes you can have a bit of deflection say from a lintel or above a door. Most cracks are nothing to worry about. If you have a crack internally look at the outside wall and if the bricks are cracked through the middle it could indicate subsidence however this is not the end of the wall and can be repaired with underpinning

Hi minnie, Could start either way, even from the middle out. Best to get someone to look at it, you can only guess from here...

What came first the chicken or the egg ?