Brain Structure
By using neuroimaging techniques, scientists have shown that some abnormal problems in the brain structure would cause social anxiety disorder. Amygdala is an important region that is responsible for regulating your fear responses. When the blood flow to this region is increased due to some conditions, it would lead to a heightened response to fears, thus triggering anxiety in many social settings. In other words, the brains of patients with the disorder tend to react differently to social situations than those without the condition. [7]
