Abnormalities in a brain neurotransmitter called gamma-aminobutyric acid — which are often inherited — may make a person susceptible to GAD. Life events, both early life traumas and current life experiences, are probably necessary to trigger the episodes of anxiety.
There is a multitude of sources that could be triggering your anxiety, such as environmental factors like a job or personal relationship, medical conditions, traumatic past experiences – even genetics plays a role, points out Medical News Today