Dr. Bradley Nelson developed The Emotion Code as a way to simply and speedily release the stored or trapped emotions that we unknowingly carry around with us.  A progression of this was his discovery that most of us (93%) have constructed a heart wall. 

This is exactly what it sounds like - a wall built around our hearts to protect us from further pain. This wall is formed from the trapped emotions we have already stored in our bodies and energetic fields. 

Heart wall clearing is slightly different inasmuch it can take about 3 or 4 sessions - it varies from person to person. 

Children also have them but theirs can usually be cleared in one session, as they are unlikely to have as many trapped emotions, simply because they have not lived through as many life experiences as us adults. 

As we subconsciously shut down or shield ourselves, it can stop us from being able to give out love fully, or to be able to fully receive any that radiates towards us. Consequently, we are limited to living a life not wholly connected to those around us. 

(This is applicable to romantic love, but all relationships with the people we love can be stilted and stunted until the heart wall is cleared.)

And surprisingly - or not - animals can have them too.