The evolution of medicine is as old as the man himself. Every civilization had its own system of medicine, so too is Greek civilization. Unani Medicine (Greek Medicine) rose from the land of Greece (Unan) gained ground rapidly and bestrode other contemporary arts of healing. Unani Medicine, the first scientific medicine, now considered as a form of traditional medicine, is widely practiced in India and the Indian subcontinent. It is based on the teachings of Hippocrates, Galen, and developed in to an elaborate medical System by Arab and Persian physicians, such as Rhazes, Avicenna and many others. Unani medicine first arrived in India around 12-13^th century C.E. with establishment of Delhi Sultanate. Unani classical literature comprises of thousands of books at various part of the world; contain vast knowledge and mention of all aspect of medicine. It traces its medical armamentarium from ancient Babylonian temples, Egyptian pyramids, Greek philosophical moorings, Roman experimentations, and Arabic, Chinese and Indian medieval practices. The system has assimilated the best  of the eastern ancient wisdom regarding healthy living as its classical literature estimates to several hundred manuscripts written in Persian, Urdu and Arabic languages by people of wide varied ethnicities and geographical regions. Most  of the pioneers  of Unani medicine have been put on pedestal as the fathers of various disciplines of science, viz. Hippocrates, the father of medicine; Theophrastus, the father of botany; Aristotle, the father of zoology; Diascorides, the author of first illustrated book on plant origin drugs; Jabir, the father of Arab alchemy. Diascorides’ De- Materia Medica and Arab alchemy latter became the basis of modern pharmacy. Of all the towering personalities of Unani medicine, Hippocrates is the most revolutionary figure who completely changed the dimensions of medicine and gave it a definite shape by putting forward the humoral theory of diseases and eliminating the concept of evil spirits as the causative factor of diseases. The history of Unani medicine emanates since the period of Aesculapius (1200 B.C.) who was the father of two Hygeia and Panacea. Hygeia was worshipped as the goddess of health and Panacea as the goddess of medicine. Panacea and Hygeia gave rise to two dynasties of medicine viz. curative medicine and preventive medicine with different philosophies.

Hippocrates’ letters and writings as compiled later by Alexandrian scholars into the “Corpus Hippocratum” encompass description of all branches of medicine. Hippocratic Oath sworn to all medical graduates has become the keystone of medical ethics. Hippocrates studied the entities such as climate, water, clothing, diet, habits of eating and drinking and their causal relation with the production of disease. The theories of Hippocrates were followed by practical enrichment of Unani medicine contributed by Herophilus known as father of anatomy. He was   the first to base his conclusions on dissection of human body. He recognized the brain as the centre of nervous system and distinguishes the motor from the sensory nerves and accurately described the eye, brain, liver, pancreas, salivary glands and genital organs. Herophilus discovered that arteries contain blood not air. 

Basic Principles:
Unani Medicine, in essence, believes in dynamic, peaceful co-existence with natural surroundings. The basic difference in approach to health lies in its existential postulate that the whole of universe is the manifestation of a universal principle of life acting through the instrumentality of the forms. It views a human as an indivisible part of larger cosmos wherein disturbance in any part affects his/her prerequisite bio-socio-psychological milieu responsible for healthy life. It not only charts out the means for the cure of disease but also explains in detail how to remain healthy. Various approaches to cure disease are a stepwise progression from physical regimens, diet alteration and use of drugs, keeping open the surgery as a last resort. The theoretical framework of Unani Medicine is based on the philosophy of Hippocrates. Any cause of diseases is countered by Tabiat (the power of body to keep milieu interior balanced). Failure to this power leads to abnormal humoral balance which in turn causes changes in the body and exhibits the disease.

Hippocrates’ humoral theory suggests that body fluids contain four types of humors called Akhlat - Dam (blood), Balgham (phlegm); Safra (yellow bile) and Sauda (black bile).These humors are present in the body in a balanced proportion, maintaining the health. As soon as this equilibrium among the humors is altered due to any cause, disease ensues. Each person's unique mixture of these substances determines his temperament as: (1) Sanguine temperament (predominance of blood), (2) phlegmatic temperament (predominance of phlegm), (3) Choleric temperament (predominance of yellow bile), (4) melancholic temperament (predominance of black bile). As long as these humours are in balance, the body is in the state of health. 

The most distinguishing features of Unani medicine is concepts of Tabiat. It is like an abstraction that cannot be observed but its myriad function is observable. It is defined as the intimation of every movement and repose. Galen defined Tabiyat as super planner of the body. It resists and opposes every derangement by bringing appropriate changes. It comprises seven principles called Umoore tabiyah. Body is composed of these seven components namely: (1) Arkan (elements), (2) Mizaj (temperament), (3) Akhlat (humours-body fluids), (4) Aaza (organs), (5) Arwah (vital spirit), (6) Quwa (faculties or powers), and (7) Afaal (functions). According to Unani Medicine, all the creations in the nature are composed of four elements. The human body is also constituted with these four elements namely-(1) Nar (fire), (2) Hawa (air), (3) Ma (water), (4) Arz (earth). Each of these elements is endowed with inherent binary qualities i.e. fire is hot and dry in nature, air is hot and wet, water is cold and wet, and earth is cold and dry. In fact these four elements are four states of matter wherein hawa stands for gaseous elements, Ma stands for liquid elements, arz for solid elements and Nar for the matter which has been transformed into heat energy. Different creations existing in the universe come into being by interaction of these four elements in different quantities contrary qualities of these elements counteract with each other and a new quality develops in compound which is different from the original qualities of participating elements. This new quality developed in the component known as its mizaj. Thus everything present in this world possesses its own unique temperament, which is in keeping with the functions, to be performed by that compound body. The human being has been constituted with the best proportion of elements and thus bestowed upon with the best temperament to deliver the best functions, which other species are incapable to perform. The human body comprises four body fluids namely –Dam (blood), Balgham (phlegm), Safra (yellow bile) and Sauda (black bile),constituted by initiation of different proportion of all four arkan. Dam is hot and wet in temperament, Balgham is cold and wet, Safra is hot and dry and Sauda is cold and dry. The mizaj of a man is expressed by the preponderance of a particular khilt present in his body. Thus a man may be damvi (sanguineous), Balghami (phlegmatic), Safravi (choleric) or saudavi (melancholic) in nature according to the preponderance of dam, balgham, safra or sauda respectively. According to the nazariya akhlat (theory of humours) - the body contains four humours in the body. The health is preserved until these humours are maintained in proportion according to their quantity or /and quality, the disease develops as soon as balanced proportion of these akhlat is disturbed in their quantity and/or quality. With the disruption of right balance among four humours, the normal mizaj of a person deteriorates to ill temperament marking the illness. In Unani medicine different measures are adopted as the treatment to bring the normal mizaj back to get rid of the disease. 

For every living being certain functions are vital to preserve the life. For these functions to take place, certain power is prerequisite. According to Unani medicine, there are three types of Quwa (power) inherent in every human being to maintain the life and propagate the generation. 

(1) Quwate Tabiyah (natural faculty), (2) Quwate nafsania (psychic and mental faculty) and (3) Quwate haywaniya (vital faculty) are the three powers present in human body. Each and every organ is furnished with a power through which physiological functions are performed. Quwae tabiyah (natural faculties) are those which serve the function of nutrition, growth and reproduction in the body and expel out the waste products from the body for the preservation of individual as well as species. Liver is the principal organ of this quwat. Quwae nafsania (mental faculty) are those faculties which perform intellectual sensory and motor functions in the body. Brain is the principal organ of this quwat. Quwae haywania (vital faculty) are those which provide vitality to the organ to enable them to receive quwat nafsania to accomplish various activity of life. Heart is the principal organ of this faculty.  

Concept of health and disease
According to Unani medicine, health is attributed to the equilibrium of akhlat (humours) in the body while disease occurs due to disturbances in the equilibrium of quantity and quality of akhlat. There is always a cause behind the origin of a disease. Unani medicine has established a very comprehensive system of classification of asbab (causes) which cover almost all prevalent causes of all disease under various categories. These are: 

Asbab Dakhilia (internal causes) deals with the diseases caused by sue mizaj (ill temperament) or sue tarkeeb (structural malformation of body organs).Asbab Kharjiya (external causes) is very important group of causes and encompasses almost all causes, emotional, physical, chemical, microbes etc, which directly or indirectly affect the equilibrium of human body. They are necessary for the maintenance of health, but an unnatural change in these factors becomes the cause of disease. These factors are called Asbabe Sitta Zarooriya (six essential factors): (1) Hawa (air), (2) Makoolat wa mashroobat, (3) Harkat wa sukoon badni, (4) Harkat wa sukoon nafsani, (5) Naum wa yaqza, (6) Ihtibas wa istifragh. 

These are called six essential factors as no human being is out of sphere of forces of these factors and has to experience and deal with them in his daily life. The disease produced due to the above described causes manifest in three forms, which make three broad categories of disease comprising almost all disorders. These are as follows:

(1)  Amraz sue mizaj, (2) Amraz sue tarkeeb, (3) Amraz tafarruqe ittisal

Amraze sue mizaj deal with the disease occurring due to abnormal change in the temperament of an organ, system, whole body. It leads to deterioration in the functions of the involved organ etc.

Amraze sue tarkeeb means an abnormality in the structure of an organ or system. This abnormality may either be congenital or acquired as a sequel to disease or a direct cause.

Amraz tafarruq ittisal: this is the group of diseases which represent the discontinuity in the structure of an organ. This discontinuity in the structure may occur due to trauma or any other disease process. Discontinuity in bone called as ‘Kasr’ (fracture). Likewise discontinuity in membrane is known as ‘Fataq’ (hernia). The disease may be sub classified into various specific categories like....

(1) Amraz Mufrad (simple disease) and Amraze murakkab (compound disease), (2) Amraz mutaddiya (infectious diseases), (3) Amraz mutawarisa (hereditary disease), (4) Amraz zahira wa batina (external and internal diseases), (5) Amraz hadda wa muzmina (acute and chronic diseases), (6) Amraz asliya wa shirkiya (primary and secondary diseases. 

Principles of diagnosis:
The diagnosis is based on the presenting symptoms of a disease; Inspection, palpation and percussion of different parts is the integral part of examination of a patient; however, muaina nabz (feeling of pulse), mushahidae boul wa baraz (examination of urine and faeces) and finally assessment of mizaj are the most distinguished tools for the diagnosis of a disease. It has already been discussed that there are four kinds of temperament, damvi, balghami, safravi and saudavi, determined by the preponderance of a khilt (humour) present in the body. Usually the normal inherent mizaj of a person changes during an illness. This is called as sue mizaj and needs to be corrected to regain health. There are ten determinants, analysis of which, establishes the prevailing mizaj in a patient. These determinants are called as ajnase ashrae mizaj. These are as follows: 

(1)Malmas, (2) Laham wa shaham ,(3) Shaar, (4)Laun al badan (body complexion), (5) Sahna /Haiyat al aza (physique) ,(6)Kaifiyat e infal (responsiveness of organs),(7)Naum wa yaqza (sleep and wakefulness), (8)Afaal ul aza (functions of organs),(9) Fuzlate badan (excreta of body,(10) Infalat e nafsnia  

After determination of mizaj, the diagnosis is corroborated by the findings of pulse. There are several hundred pulses found in a gamut of disease and there is a specific pulse for a specific body condition or internal milieu. 

There are ten features to constitute a nabz (pulse).These ten features are meticulously felt to find, if these characters are normal or abnormal. These ten features are as follows: (1)Miqdar e imbesat  (degree of expansion), (2) Kaifiyat e qarah (impaction on the fingers), (3) Zamana e harkat (duration of movement), (4) Qiwam e ala (texture of artery), (5)Khala wa imtala ( emptiness and fullness of artery), (6)Malmas (feeling of hot or cold, (7) Zamanae sukoon (duration of rest), (8) Istawa wa ikhtalaf (equality or inequality), (9)Nizam wa adme nizam(regularity or irregularity), (10) Wazan (rhythm) 

These features produce hundreds of pulses through permutations. Few of them have been given a specific name and need special mention here-

(1)Nabz  ghazali (jerking pulse),(2)Nabz mauji (wavy/undulant pulse), (3)Nabz doodi (vermicular pulse),(4)Nabz minshari (serrate pulse),(5)Nabze masali (decustate pulse), (6) Nabze zanbul far (mouse tail like pulse),(7)Nabz zul fitra (dicrotic pulse),(8)Nabz waqe fil wast (intermittent pulse),(9)Nabz mitraqi (hammer like pulse), (10) Nabz tashannuji (spasmodic pulse),(11)Nabz muntaish (tremulous pulse) (12) Nabz zul qaratain (double stroke pulse), (13)Nabz namli (ant like pulse),(14) Nabz mutavatir (tense pulse) 

After finding a corresponding pulse in a disease, the diagnosis may further be confirmed by examination of baul (urine). There are seven characteristic features in urine; these are examined keenly to find any abnormality in them. They are as follows:

(1)Laun (colour), (2) Qiwam (consistency), (3)Safai wa kadoorat (clarity and turbidity) , (4) Boo (odour), (5) Jhag / kaf (foam), (6) Rasub (sediment) , (7)Miqdaar (quantity)

The above described features may change abnormally during a disease and produce characteristic urine found in that specific disease entity.

Sometime examination of stool also contributes in the diagnosis of various diseases. Following characteristic of stools are examined in order to diagnose a disease.

(1)Miqdaar e baraaz (quantity of stool), (2) Qiwam e baraaz (consistency of stool), (3)Laun e baraaz (colour of stool) 

Principles of treatment:
The treatment is broadly divided into three courses of therapies.

(1) Ilaj bil tadbeer (regimental therapy), (2) Ilaj bil dawa (pharmacotherapy) (3) Ilaj bil yad (surgical therapy) 

Ilaj Bit tadbeer:
This is a form of treatment, wherein asbab sitta zarooriya are modified either to preserve health or to get rid of the disease.

These six essential factors have already been described, course of action of these factors is manipulated in various ways to support the treatment, and makoolat wa mashroobat (foods and drinks) is one integral part of them.

 Diet on one hand is believed to fight against the disease by providing energy to Tabiat, while on the other hand injudicious use increases the morbid material responsible for the disease and thus aggravate the problem. Hence the diet is modified in its quantity and quality to cure the disease condition. Usually diet reduced in quantity in acute diseases while a moderate diet is prescribed in chronic debilitating diseases.

 Likewise appropriate adjustment in other factor is also made in order to provide best recuperative condition to the patients. Istifragh (elimination) forms the mainstay of maddi amraz (disease involving matter) the morbid material through various procedures is eliminated from the body to cure the disease. All such procedures come under istafragh. Sometime the morbid material is diverted from important organs like brain, heart, liver etc. to organs of lesser importance to safeguard those important organs from deleterious effects of obnoxious matters. Few such therapies which either eliminate or divert the morbid material are described below. Ishal (purgation) Qai (emesis) Idrar (diuresis) Hijamat (cupping) Dalak (massage) Riyazat (exercise) Hammam (bathing)    Tareeq (diaphoresis) Irsale alaq (leeching) Fasd (venesection) Huqna (enema) Nutool (irrigation) Inkabab (inhalation) Tanfees (expectoration) Takmeed (fomentation) Imala (diversion) Amle kai (cauterization) Ilam (counter irritation) Aabzan (hydration therapy) Pashoya (foot bathing)

 Ilaj bil dawa:
The disease usually occurs due to alteration in the nature of asbab sitta zarooriya. These changes become the predisposing factor and /or exciting factor to dismantle the equilibrium of four akhlat to produce a disease. The new condition in body exhibits its own abnormal temperament with associated malfunctions. The temperament of the produced disease may be according to the preponderance of four akhlat i.e. damvi, balghami, safravi and saudavi. Physiologically the disease may be bracketed under sue mizaj (ill temperament) which, if severe or longstanding may cause sue tarkeeb (structural malformation) in an organ to restore the health the sue mizaj has to be back tracked to previous normal temperament.

According to Unani medicine, the basic tenet of treatment is “Ilaj bil zid” (Principle of opposition), which explains that ‘a certain disease entity with certain degree of abnormal quality and quantity of akhlat begets drug of corresponding degree and opposite quality and quantity to counteract a disease’. Sometimes only any one of four qualities may simply become excessive in an organ but madda (matter) is not affected, this is called sue mizaj sada (simple ill temperament). In the treatment of sue mizaj sada, those tadabeer are adopted which counteract the abnormal excessive hararat or baroodat, ratoobat or yaboosat. If the sabab (cause) is much strong and stays for a long time, the matter usually khilt is affected producing sue mizaj maddi. Thus an abnormal khilt is produced the excess of which brings about imbalance in the equilibrium of akhlat, producing sue mizaj damvi or sue mizaj balghami or sue mizaj safravi or sue mizaj saudavi.

The treatment of sue mizaj maddi is different from sue mizaj sada. As madda is affected in sue mizaj maddi, it has to be modified in its consistency for easy elimination from the tissues of the organ. This process is called as nuzj (concoction), brought about by munzijat (coctives) specified separately for every khilt. Nuzj is followed by istafragh .The various means of which have been described under heading of istafragh. After elimination of morbid matter, the organ regains its previous normal temperament and starts functioning normally. Sometimes when the organ is sluggish even after regaining normal mizaj, tadeel and taqwiyat (normalization and Potentiation) is required; this is achieved by instituting muqavviyat of conjured organ

Ilaj bil yad / Jarahat (surgical treatment):
Disease which occur, few of them due to sue tarkeeb and most due to tafarruqe ittisal are treated with surgery. Surgical treatment in Unani medicine is not as well developed as in mainstream medicine and state of the art machinery of modern surgery has bestrode almost all other indigenous surgical practices, although in hey days of Unani medicine during Arab period, the stalwart of surgery like Abul Qasim Zahravi, had elevated the art of surgery many notches by inventing new surgical instruments and novel techniques of surgical operation.