"Psychoneuroimmunology is an interdisciplinary scientific field devoted to the study and investigation of the mechanisms of interaction and communication between the brain (mind/behavior) and the systems responsible for the homeostatic maintenance of the organism, the nervous (central and autonomic), immune and neuroendocrine systems, as well as their clinical implications."
George F. Solomon

PNI investigates, above all, the physiological functioning of the neuroimmune system, disorders of the neuroimmune system and the physical, chemical and physiological characteristics, mainly, of the detectable components in peripheral blood of the neuroimmune system in the laboratory (in vitro), in the living organism (in vivo) or in the place where the research takes place (in situ). It is also called Psychoimmunology or Neuroimmunomodulation.

An important pillar of it, in clinic, includes orthomolecular medicine defined as:
The maintenance of good health and the treatment of diseases through changing the concentrations of substances in the human body , which are normally present in it and are essential for health (Linus Pauling Nobel Prize in chemistry 1954 and Peace Prize in 1962).
Food has been used as medicine since ancient times and it is worth making a special mention of Hippocrates (370-430 BC), the first European physician who separated medical science from natural philosophy, leaving for history such inspiring phrases in clinical practice as:
*WHATEVER IS THE FATHER OF A DISEASE, THE MOTHER IS ALWAYS A BAD DIET".
*WHEN SOMEONE DESIRES HEALTH, IT IS NECESSARY TO ASK HIM FIRST IF HE IS
FIRST IF HE IS WILLING TO SUPPRESS THE CAUSES OF HIS ILLNESS...ONLY THEN CAN WE HELP HIM."
Orthomolecular medicine uses mainly foods and micronutrients isolated from plants and fruits. Phytotherapy is medicine that uses whole herbs and plants and/or their extracts.
"AT FISICSALUD WE CONSIDER LIFESTYLE, NUTRITION AND PHYSICAL ACTIVITY TO BE THE MOST INFLUENTIAL TARGETS OF INTERVENTION IN RESTORING AND MAINTAINING HEALTH."