Agoraphobia is a phobia or fear of being in a place where you feel unsafe or trapped. People experience intense fear and feelings of panic accompanied by a strong urge to escape to a place they feel safe (most commonly home). Often the feared place is somewhere that can be hard to ‘escape’ from, such as a crowded shopping centre.
Over time, people experiencing agoraphobia may start to avoid more and more places. Unfortunately, this creates a vicious cycle - by avoiding feared places you never learn that the anxiety can be managed. This can mean that life can become severely limited, e.g. not leaving the house or only doing so with a trusted person.
The underlying reasons why someone may feel this fearful are not always straightforward. It might be helpful to talk to a professional to help you work out what is going on and why you are feeling unsafe. Even if you don't know why you feel like this, the above things can still help.
Anxiety and Panic attacks
Mental Health Foundation podcasts
NHS Choices Apps