The human body is a self healing and self regulating organism. (i.e breathing, healing from paper cut, pumping of the heart) The Nervous System is the master system and controller of the body. Therefore, if the Nervous System function is interfered with, it hinders the ability of the body to heal and regulate.
We know that when the body is under stress (i.e Chemical, Physical, Emotional), it adversely affects neurological functions and changes in the body tension pattern around the spine. When a Chiropractor identifies a misalignment in a tension pattern, we call it Subluxation.
(Subluxation is a sign that someone is under certain form of stress that is beyond their body general adaptive potential which is not to the point of death but enough that their body is unable to fully functions.)
We identify the pattern of Subluxation in the Nervous System, apply an adjustment that is corrective in nature, and see if the pattern changes and neurological performance improve. When that happens, we know that the person is on their way to getting healthier.