For many people social anxiety and social phobia creates significant problems in their lives, often without them knowing the root cause. The issues created via social anxiety and social phobia can seep out into every aspect of your life: perhaps you choose to live alone, or begin to avoid social interactions; you lack confidence in your abilities and your lack of confidence creates difficulties on your work; you fail to get appointed to jobs you are more than capable of doing due to your lack of faith in yourself and this leads to others questioning your abilities too; you may dress in dull or dark colours to try and hide yourself, or perhaps you over-eat as a way of avoiding unwanted attention and/or flattery; you don’t challenge others in order to avoid conflict; or you may be chronically insecure about your relationships with others which can progressively undermine even the strongest of relationships.
There are few statistics about the extent to which people suffer with social anxiety and social phobia, and those that are published come with hefty health warnings about the likely inaccuracies. What we do know though is that almost everyone, at some stage in their life will experience feelings related to social anxiety.

Social-anxiety.org.uk state:

Millions of people around the world suffer from Social Anxiety Disorder (also known as Social Phobia) and related conditions. Despite being the most common type of anxiety disorder and the cause of much impairment and suffering, it is under-recognised and under-treated.
However, perhaps because by its very nature sufferers of Social Anxiety are reluctant to talk about their problems or seek help, the condition is still not widely known amongst the general public, and was only recognized as a disorder in its own right as recently as 1980.