It’s not unusual to feel fearful or scared as a young child and is usually just a phase but when it begins to be excessive fear or worry in kids 6 and over and lasts for a period longer than 4 weeks it can be anxiety.
Anxiety occurs when a child suffers excessive distress and becomes nervous or fearful. It can be triggered by a circumstance that the child feels is traumatic, a significant family change such as divorce, birth of sibling, first day of school, death in the family or just a scary event that the child personally experiences.