What caused shyness and what can be done about it?

Shyness may come from genetic trait as their is a actual episode of grey's anatomy about shyness.

Or

shyness is usually caused by fear, rejection, attraction, lack of self-confidence, social skills, etc. However i don't think there is much to do about it but if you are truly affected by it, there are medical procedures and treatments for it.

Hope this works