The anxious child
It is completely normal for children to feel anxious from time to time, but some experience this more than others. It is important to keep an eye on how your child is feeling, and how they are dealing with this.
Increased anxiety can be a result of a developing imagination, and therefore ability to predict the future and possible events. It could also be from recalling past events - if you think your child is anxious about an event that has happened ensure you discuss this with them.
Your child is also picking up the ability to listen to adult conversations that he or she is not meant to hear. Be mindful of this, and if your child has older siblings make sure you remind them too.
In addition, there are a few typical fears that children tend to experience; fear of the dark, shyness, separation, etc.
The best thing you can do for your anxious child is to talk to them about their fears, and acknowledge that being worried and scared is normal. You do not want your child to bottle it up - start an open conversation that your child knows they can revisit at any time.