Social Anxiety Disorder is one of the most common forms of anxiety.
Everyone has some degree of social anxiety, however it becomes an issue when it starts affecting your life.
For instance, most people get a little anxious when they have to have a talk with their boss or maybe even speaking in front of a few people, this is a normal level of anxiety.
However, when it starts affecting ones life, like not going to certain functions due to their anxiety or maybe even not wanting to leave the house.
This is when the anxiety needs to be addressed.
So, what causes social anxiety disorder? There are a few contributing factors to social anxiety including:

• Genetics - As we know, many types of things are passed down from generation to generation.
  Anxiety is no exception.
  Just as a health problem, an addiction problem or depression can be passed down, anxiety can too and this can make someone more likely to suffer from anxiety.
  
• Development - Anxiety can develop over time due to different situations that occur in ones life.
  Starting at around 7 months, a baby can experience fear of some people, a few years later a child may experience some type of separation anxiety, or at any time in ones life they can experience a traumatic event that can cause the on set of anxiety.
  
• Chemical Imbalance - Quite often symptoms of long-term social anxiety disorder can be attributed to a chemical imbalance in the brain.
  Neurotransmitters in the brain are what directly affect the way one feels about a certain situation or thought that may arise.
  

As you can see there are a few factors that can play a role in developing social anxiety disorder.
Some people may have only one of these factors that contribute where others may have more than one of these factors that contribute to their anxiety.
No matter what caused the anxiety, there is always a way to get help and cure it.