Cracks in brick walls are difficult to assess just looking at a single view . This is because it is necessary to determine whether a portion of the wall structure is still moving and why they moved, which requires a period of observation. There are many reasons that can cause a vertical crack on a wall, but finding the underlying cause is the hardest.
brick wall

Initial Assessment
On a large piece of paper, draw a pencil sketch of your house or wall. Make all visible cracks you can find. Takes note of its length and see if they continue beyond the brick through the structure. Inspect the interior of the house and notes on the finish cracks or doors that do not close properly. If you see cracks inside, looking for evidence of patching or repairs . The doors do not close properly can give evidence that a part of the house has settled wrong, so that makes door frames are out of alignment. It also notes the width of each crack. See each wall from the side, to see if leaning out from the center, which can be an indicator that the side retaining wall systems have been damaged.

Did the crack moves a little?
This is the most difficult to assess, since you’re trying to estimate future consequences by a perception in the present. If the crack is still moving, it means that the problem is increasing. The age of the crack can provide some clues to this. If the edges of the crack are worn or there is accumulated within the same residue, this may be evidence that the crack is very old and stable. A crack that has been recently resanada and opened again, is strong evidence that the crack is still moving. Special devices for monitoring cracks can be installed on either side of the crack, they provide a more definitive answer to whether the crack is still moving and in which direction.
Why has moved?
Determine why a crack is formed, demand some experience and knowledge of construction techniques. Common to explain why the appearance of one, causes are: thermal expansion and contraction of materials, the foundations, the root of a tree, a frost heave, faulty connection between two sections of the house and structural component failures. A vertical crack on the end of a wall often indicates thermal expansion or moisture from the masonry. This can be a problem in the long brick walls that were built without adequate expansion joints.

What are the implications?
It is almost impossible to give a definitive answer about the consequences that can result from the existence of cracks in the walls, as this requires predicting the future movement. If there is sufficient evidence that the crack is moving, is wider than a hairline or the wall is leaning, certainly should ask a specialist to come to do further evaluation.