Does your child struggle to make friends with other children or hide behind you when he meets people unfamiliar to him? Shyness in children is not a disorder, but simply an aspect of his character, and should not generate much concern.
Psychologists do not associate psychological distress with shyness in children, and it is not something that impairs his social functioning. All it takes is a little patience and a little help, and in most cases everything will work out for the best.
In any case, to alleviate your worries, it might be helpful to learn more, and also to read some tips on how to help your child in relating to others.