This type of question is usually the result of suspicions that come from noticing cracks in concrete, bricks, drywall, or doors or windows that do not operate correctly. In other words when you see something wrong with your house that you never noticed. To better understand the answer, a general knowledge of the structure of a house is helpful.
The structure of a house holds everything together, supports the roof which provides protection, and provides the framework for the various systems and finishes. It generally consists of the foundation upon which everything rests, the wall framing, ceiling joists and beams, and attic framing which includes the rafters. It is comprised of hundreds of pieces which, when properly assembled creates a unitized whole that is much stronger than the individual parts. Since we live in the real world that is governed by the laws of physics, most of the forces exerted on the structure are gravity loads which push down on all the components until they reach the foundation. In the building industry these are referred to as “dead loads” because they do not change. Added to gravity loads are “live loads” which can change dramatically. They can include the weight of people, furniture, a bathtub filled with water and big SUV’s (in the garage). Huge live loads can be imposed on the walls and roof by wind and snow pushing against the house. The manner in which all these loads are transferred from the point of origin (a strong wind blowing on the roof) through the various rafters, beams, posts and walls down to the foundation is referred to in the construction design industry as the load path. Any interruption or break in the load path can result in structural problems.
The removal of a load bearing wall changes the load bath as originally designed. The loads which originally transferred through the wall to the foundation must be adequately addressed by installing a beam to replace the wall. But the beam takes all the load of the wall and directs it to concentrated points at each end of the beam. If the foundation cannot support the new concentrated loads, structural problems may result.
Large trees near the foundation can adversely affect the performance of the foundation. Large trees can suck the water out of the ground and cause the foundation to sink. Some roots are strong enough to heave the foundation. Such interruptions in the load path can result in structural issues.
The causes of structural issues are as varied as the way they may show up. For this reason, a competent professional should be contacted to determine the cause and develop a proper course of repair for suspected structural problems.