The only fears we are born with are falling and loud sounds. Other fears we learn. We learn something we can unlearn it. If you have a fear which is above a 7/10 then it is phobia.
This may be lifts, flying, certain foods, the tube, people.. the list could go on. Whatever it may be your body and mind has learnt how to respond in a certain way. It may have been from a traumatic experience or you may have no idea at all where it came from.
We break those habits and thought processes. We also reduce the intensity of the feelings which allows for more rational, controlled responses to take over.
There are many ways we can do it and its a process of seeing what works best for you. I also teach clients ways in which they can break the thought processes themselves to help them gain confidence that they are always in control. Once you feel the control you feel confident that you can handle any situation.
For simple phobias then 1-2 sessions are needed but if the issue is a little more complex then 3 sessions are recommended to track progress.