It is a detailed science of correspondences between the mind and body. There is book written on the subject by Louis Haye. But broadly speaking the location of the organ and the corresponding psychological centre gives a quick reference point.
For instance headache would correspond to some burden while neck and shoulder responsibilities. Lungs signify the way we receive and expend our vital energy. The heart is sensitive to emotions as well as push for achievement and ambition. Stomach is about digesting unwanted feelings while liver responds to bitterness. Kidneys is about holding back certain lower vital movements while the naval region has to do with fear, anger, excitement. Pelvis, uterus, bladder is connected to movements related to reproduction including sexuality. The spine in general is about the ability to take the challenges of life while lower back is about the feelings of loss of support as well as blocked sexuality and anger. Limbs express the capacity to reach out and grasp and walk. Hair and nail and teeth represent the Inconscient. Eyes and ears about what we are receiving from the world.
But these are not absolute rules and in these subtle matters the total picture is as important as the symptom.
Affectionately,
Alok Da