Many physical difficulties that people face as diseases take place at the boundary between the self and the world, between the self and life.
At this boundary exist attitudes that relate to trust of others, of life, of God, and the capacity to surrender the ego-self to something greater.
At this boundary also exist fears of harm coming to oneself, memories of past dangers - perceived or real, and all that creates a sense of un-safety in the world.
Many immune disorders, deficiencies, and diseases, before they became physical problems, were aspects of consciousness, often related to the boundary between the self and world. On the physical level, such a consciousness can create a vulnerability to the transmission of harmful substances, energies, or microbial organisms from the environment into one's body, and the inability of the physical boundary known as the immune system to prevent that. Sometimes this boundary is too thick. Sometimes it is too thin. Normal immune functioning that acts as a filter and that is part of the body's natural state require a properly functioning balance of energies between what is inside and what is outside. Only then can what is good be let in and what is harmful be kept out.
This is true on both the physical level and on the psychological level as well. Indeed, there is a parallel between what exists at the physical level and what exists within consciousness, not necessarily detail for detail, but in an overall sense of good health being dependent upon the proper flow of energies between the self and the world.
Often, such health is realized through the healing of issues between self and others and between self and not-self. This takes place as one learns to say "yes" and "no" - "yes" to that which is light-filled and harmonious with one's higher truth and nature, and "no" to that which creates negativity, fear, and limitation.
Boundaries between self and not-self can be too thick or too thin, in either case creating problems with the flow of energy back and forth. An increased ability to create a boundary where little or none existed before, for some people has a direct bearing on the healing of immune difficulties. On the other hand, an increased ability to let go of separation, distancing, and projection and to reduce the boundary between self and others, can, for other people, also create a healing of boundary issues.
No matter what the physical problem, in addition to addressing the symptom picture as common sense would require on the physical level, one must also and more deeply seek the source of this problem in consciousness, for when deeper attitudes, motivations, beliefs, and fears are altered, so, too, will the physical condition alter.