I just finished reading 'Quiet: The Power of Introverts in a World that Can't Stop Talking' by Susan Cain. In it, she mentions the 'highly sensitive person', a term introduced by Elaine Aron. Aron has written a few books on the topic and has a PhD in psychology. I've been reading more about this type of person as I believe that many of my family members meet this profile (including my son, and possibly me). I've come across a few links that you might find helpful.
First, a self-test: http://www.hsperson.com/pages/test.htm
Second, an article re. highly sensitive people and giftedness: http://www.hsperson.com/pages/3Nov04.htm
Third, a test for kids: http://www.hsperson.com/pages/test_child.htm

Although I haven't read it yet, I suspect that her book provides coping strategies for people who are highly sensitive. In Cain's book, she talks about finding restorative niches to hide out from the world as needed. Both authors discuss this trait as biologically defined, in that some people react more strongly (and physically) to external stimuli, such as noises, smells, sights, etc. However, the environment you live in can shape how you cope (particularly in terms of anxiety, depression, etc.).