Anxiety is essentially our body's reaction to stress. It usually manifests itself as feeling afraid or apprehensive of something in the near future, often out of your control or in unknown circumstances. The classic symptoms of anxiety are sweating, unable to sit still, difficulty sleeping, overthinking and ruminating on things, increased heart rate and rapid breathing. However anxiety can present itself in many different ways, from skin and stomach problems, to muscle twitches or obsessive behaviour.
Anxiety is a normal reaction to things which concern us, as we all have things in our lives which can make us feel nervous or worried. However, if you feel in a constant state of anxiety, over an extended period of time, it's often a sign that something deeper needs to be addressed.