While shyness can be crippling in the young, it has a shelf-life.
The sheer terror of social interaction for children or young people can be strong enough to induce debilitating physical symptoms - blushing, shaking, stammering, sweating hands, even the welling up of tears - but research has shown that this is more to do with the lack of social skills, the unfamiliarity of the situation and the anticipation of that unfamiliarity than to do with a deeper form of introspection or social anxiety. While it seems like a character trait, it is more often just a symptom of the fear of the unknown.
In other words, ordinary shyness can be conquered by simply putting yourself into timidity-inducing scenarios and forcing yourself to join in; however terrible it feels the first time, the second time will be exponentially better. Parents of naturally shy children are pivotal in influencing which way that shyness will go - gently handled and carefully introduced into non-threatening gatherings where they can develop their social skills at their own pace, these children will gradually shrug off their shyness.
But if parents constantly excuse their children in front of others, "I'm sorry, little Charlotte is awfully shy" or actively tease or criticise them for their shyness, "See how Charlotte blushes!" and do nothing to soothe the underlying anxiety, then they should not be surprised when the shyness escalates.
Beyond the age of thirty, however, shyness becomes less excusable; often it is used as a tool by the arrogant or lazy to dodge the need to interact with people. That person who tells you that they hate going to drinks parties because they are too shy to talk to people is usually inadvertently confessing that they are too idle to make the effort.