Physiologically, our bodies are designed to store emotions in a part of the brain called the Limbic system. The effective reason for this would be if a child reaches up to the hot stove and burns his fingers, this emotional memory will be deep seeded in memory so the child will not make the same mistake twice.
The dysfunction of this is that when we have an incident in life, fueled by emotion, our Limbic system takes that incident and makes it part of our cellular body, so that we will not make the same mistake twice.
In Chinese Medicine, emotions are associated with organs. For example, it is known that Liver is associated with Anger, Heart associated with Anxiety, Kidneys associated with Fear etc.
I believe that after the Limbic system gets the program of the emotion, it then begins to replicate via the DNA and integrate or transfer these emotional aspects to it's associated organ.
The Onion Layers Analogy:
As you go through life, piling up emotional misinformation, you end up 30 years later with, for example: fear of heights with no apparent reason.
To give you a visual, imagine, your first fear of the hot stove, then a strange dog barks at you, creating another fear layered on top of the hot stove, later, your teacher yells at you when you are in front of the class and so on. Because you did not release those fears as they happened, as a child would cry or scream with fright at the barking dog.
In the classroom, it is more difficult to express and generally, a person would hold in their fear, giving the Limbic system time to attach the emotion and begin replication to the Kidney tissue. As you pile up layers of emotional fears, several things can happen... you become unreasonably fearful and/or you begin to have kidney issues.
These layers are sometimes compared to the layers of an onion, with the original dysfunctional fear at the core of the onion and the layers being the teacher incident and others that lay on top of that one. The closer you can get to the core dysfunction, the more layers will come off.
In Chinese Medicine, there are many levels to disease, some deeper and more chronic than others, some more recent and acute. When recent acute issues are not addressed, they tend to become chronic and more dis-ease related.
I use several "emotional release techniques" to address both chronic and acute issues and have found great success in unblocking emotions and allowing both emotional and physical healing. Everything from fear of heights and anxiety when driving over bridges to past traumas or events.