Hi Bluebunny,
Stress is a well known trigger for a psychotic event, even relatively 'mild' levels of stress can be damaging. Schizophenia is associated with difficulties in filtering incoming information - so the person is effectively bombarded with information that they are unable to effectively discard or process in a meaningful way. This is partly why people with sz seem to misunderstand or misread information around them. People with schizophrenia 'feel' stress both physically (increased heart rate, higher blood pressure) and psychologically.
Stress can also cause damage to the brain. Cortisol, which is released as a result of stress, can damage an area of the brain known as the hippocampus. People with sz often experience problems with memory and coordination - two processes controlled by the hippocampus.
Like anyone else who is prone to stress you should take on board stress reduction techniques such as relaxation, or meditation, or yoga, etc.