Of all the traditional medical systems being practiced today, Greek Medicine has the most in common with Ayurveda.  Both systems are constitutionally based, and deal with the relative balance of certain vital fluids or humors.  Each humor or dosha has its own basic constitutional type, and mixed types exist.

Humors and Doshas

     The first big problem we confront in comparing Greek Medicine to Ayurveda is that there are four Greek humors , but only three doshas in Ayurveda.  Which is which, and what about the fourth humor?
     The first key involves the definition of the Ayurvedic term, dosha, which literally means, "fault".  The three doshas, or pathophysiological principles of Ayurveda, primarily describe three basic ways in which a perfectly balanced constitution may be "tipped" and predisposed towards certain kinds of pathologies.
     The second key comes from Galen, who considered blood, or the Sanguine humor, to be the most inherently faultless and perfect, being made from perfect nourishment perfectly digested.  In Greek Medicine, blood is considered to be the very essence of health, youth and vitality.
     The third key comes from Sushruta, an ancient Ayurvedic authority on medicine and surgery.  In the Sushruta Samhita, he states that blood, which is usually considered to be a dhatu, or tissue type in Ayurveda, could be called the fourth dosha. 
So blood, or the Sanguine humor, is the fourth dosha.  But of the other three, which is which?
     The most obvious correspondence is between phlegm and Kapha.  Cold and Wet are two important qualities of Kapha, which shares the cooling, moistening, nourishing and lubricating functions of the Phlegmatic humor.
     Similarly, in its Hot nature and association with fevers, inflammation, bilious pathologies and the like, there is a close resemblance between Pitta and the Choleric humor.  Like the Choleric humor with its Digestive Virtue, Pitta also governs digestion, metabolism and transformation.
     The correspondence that seems the most shaky and tenuous is the only one that remains.  How can Vata, derived from the light, subtle Ether and Air elements in Ayurveda, correspond with the Melancholic humor, which is the metabolic agent of the heavy, gross Earth element?
     But when one looks at their basic attributes, as well as the pathological predispositions or faults of Vata and black bile, the similarities are overwhelming, and vastly outweigh the differences. Of all the  doshas, Vata, like Melancholy, is the one most prone to pathology and disease.  Qualitatively, the pathological predispositions are also overwhelmingly similar: nervous, colicky digestive disorders; nervousness, insomnia, wasting disorders, nutritional deficiencies, arthritis and rheumatism and neuromuscular disorders.  Coldnes and Dryness, as well as the astringent taste, are also key attributes of Vata.


Vital Principles, Ayurvedic and Greek

     There's also a great similarity between the various vital principles in both the Greek and Ayurvedic systems:
     Pneuma, or the Breath of Life and its Vital Force, are clearly the equivalents of prana and vayu in Ayurveda.  They form the basis of all kinetic function in the organism.
     Ignis, or the Innate Heat of metabolism also clearly corresponds to Agni in Ayurveda.  They provide the basic thermal energy behind all pepsis, or digestion, metabolism and transformation in the organism.
     Similarly, the Radical Moisture corresponds to Ojas.  Both give nutritive integrity, finish and polish to the organs and tissues, and underly humoral immunity and the nonspecific immune resistance of the organism.  Both are contained in the procreative seed of both sexes in very concentrated form.  And both are the distilled endproduct of digestion, nutrition and metabolism.
     The only vital principle remaining is Thymos, or the immune force that powers the immune response.  My best guess is that its functions would come under the dominion of prana in Ayurveda.  What can I say, except that the Greeks loved the number four, and the Hindus the number three!


Therapeutic Similarities

     Since both Ayurveda and Greek Medicine are constitutionally based, it's not surprising that improving basic constitutional strength, resilience and resistance to disease should be a very important therapeutic objective in both systems.  The methods and modalities employed are also quite similar:  diet is first and foremost, followed by simple herbal remedies, lifestyle modification, massage and bodywork, hygienic purification treatments and exercise/gymnastics/yoga. 
     Being humorally based, both systems consider self-poisoning, or autointoxication with toxic metabolic residues and superfluous morbid humors to be the primary cause of all disease and pathology, for which they prescribe various hygienic purification treatments and regimes.  The Ayurvedic word for toxins, ama, means, "crude" or "raw" - residues from faulty or incomplete pepsis that haven't been properly integrated into the body and its functioning, and therefore impede it.  The word ama has its equivalent in the word "crudities", a common term for toxins in Greek Medicine.