Agoraphobia

ag-or-a-phob-ia (gr--fb-)

noun
1. Irrational fear of unfamiliar settings or places. This fear is often closely connected to the fear of losing control, which could lead to embarrassment and anxiety or panic attacks. This condition may or may not be social in nature. Sometimes, this condition is linked with social anxiety disorder.
Famously, Kim Bassinger was afraid of wearing pretty things because people would look at her, then she would wear plain things and worry people weren't looking at her enough, and this lead to her agoraphobia.
I'm not suffering from agoraphobia; it's just really cold outside and I'm nervous.

Synonyms: afraid, anxious, paranoia.

Note: If you are good friends with an agoraphobic person, it's not nice to throw them surprise parties at nice restaurants they've never been to before. They don't like that sort of thing.