The main causes of Schizophrenia really haven't been proven but there are certain things that are pretty certain to lay at the root of it. Genetics is one thing. It can be inherited. If a parent has it, you might get it too or your offspring might. It certainly doesn't mean that you will though. There is also the possibility of a biological reason such as an imbalance of your body's hormones and chemistry that sets the scene for Schizophrenia.
This is just a theory and has not been proven but is highly suspected and makes good sense. There are other possible reasons for Schizophrenia as well. If you are unbalanced to begin with and suffer a major trauma in your life, chances are that you would be more susceptible to coming down with Schizophrenia. That can be a trigger that sets it off initially and triggers can bring on episodes from then one.
While the exact nature of the disease cannot be for sure, there are certain traits that people with it tend to share. They do not do anything to intentionally get it and they don't get it because they are weird or crazy either. It is simply an unfortunate disease that can inflict someone, no different than any other mental condition or physical problem like cancer or Diabetes.