Worrying is the principal factor of Generalised Anxiety Disorder, but there are other specific aspects to the anxiety that occur with GAD. Worry about current problems and hypothetical situations, worry about worry, intolerance of uncertainty, cognitive avoidance and lack of problem solving skills.
A person would be experiencing worry more days than not and will have done so for at least six months. Their worry will be difficult to control and will be with regards to numerous circumstances or events.