Intranasal low intensity laser therapy (ILILT) was the clinical applications of intranasal low intensity laser irradiation in internal medicine. ILILT may be mediated through three pathways,blood,meridians and autonomic nervous system,one of which is at least far from its function-specific homeostasis. Blood pathway was directly supported by its improving blood lipid and hemorheologic behavior of patients with vascular diseases. The meridian mediated ILILT hypothesis was supported by the comparative studies of therapeutic effects of acupuncture and ILILT. The rehabilitation of ILILT might be mediated by increasing the promotion of the sirtuin.