1. Social anxiety disorder

2. Social anxiety disorder, also known as SAD or social phobia Intense fear and anxiety can happen from the following: Food consumption in front of others; being in the center of attention; asking questions and participating in a group; talking and interacting with groups or strangers; being in a crowded group and such situations where they can be watched, judged or criticized.

3. The person with SAD will be afraid of making mistakes, looking bad, and be embarrassed or humiliated by others. This fear of anxiety may lead to anticipate fearful situation and result in avoidance. The physical symptoms of SAD are pounding heart, sweating, trembling, blushing, muscle tension, irregular function of digestion and diarrhea.

4. The psychological theory is due to trauma, low self- esteem, and negative self-concepts.

5. The biological theory is due to genetic difference in the receptors and its function.

6. The socio-cultural is similar to the psychological theory; that traumatic experience in the past causes SAD.