Anxiety is actually a normal response to danger. It is a fight or flight response. It is easy to understand that when you are attacked by a tiger, you either fight or flight.
That is why whenever people get stressed, they either get angry and "fight", or they withdraw and "flight". Can you relate to this?
Chances are, you can. That is normal.
When people have an anxiety disorder or a panic disorder, this response is triggered by events that are not what we would normally consider as very dangerous e.g. standing on a balcony or driving a car. So in a way, the response is a FALSE ALARM. It is like having a security system that goes off whenever an insect crawls across the sensor. In essence, the response is normal, but the sensor's sensitivity is malfunctioning and needs resetting.
In order to reset this, one needs to be aware and learn how to "reprogram" the subconscious mind through changing cognition and behaviour. You can learn to do this through mindfulness, Cognitive Behavioural Therapy (CBT) and Acceptance Commitment Therapy (ACT). Medications like serotonin reuptake inhibitors (SSRIs/antidepressants), can be used as a treatment modality.