The word for medical sciences in Vedas is Ayurveda. The word Ayurveda comes from Sanskrit word Ayuh (life) and Veda (knowledge), means the knowledge or science of life.

Definition of Ayurveda

Charak Samhita further defines Ayurveda as:

हिताहितम सुखं दु:खमायुस्त्स्य हिताहितम l मानं च यत्रोक्त्मायुर्वेद: स उच्चयते ll

Hitahitam sukham dukham-ayus-tsya hitahitam.

Maanam cha yatroktam-ayurvedah sa uchchayte II.-Charka Samhita, SU.1.41
Ayurveda deals with good and bad life (Ayu), as well as happy and unhappy life (Ayu). It explains what promotes health and what affects health adversely. It also deals with what affects life expectancy and the quality of life. A happy person is one:

“Who is devoid of mind and body imbalances, whose senses are perfectly functioning, whose body is full of ojas (strong immunity), tejas (shine) and prana (energy), well respected, hardworking, brave, intellectual, scholar, prosperous and can perform all duties without obstacles”

Sage Sushruta defines Health as follows:

समदोषः समाग्निश्च समधातुमल क्रियः। प्रसन्नात्मेन्द्रियमनाः स्वस्थ इत्यभिधीयते। सुश्रुत सूत्रस्थानः 16∕48

sama dosha sama agnischa sama dhatu mala kriyaaha|

Prasanna atma indriya manaha swastha iti abhidheeyate || Sushruta Samhita
"Person, whose all three humors or Doshas: Vata (air), Pitta (fire) and Kapha (water) are in balance, whose appetite and digestion are in balance; whose seven body tissues (Seven dhatus: rasa, rakta, mansa, meda, majja, asthi and shukra) are functioning normally; whose malas (urine, feces and sweat) are eliminated properly and whose spirit, senses and mind (satva, rajat, tamas), remain full of bliss is considered healthy"

This verse is explained further as follows:

Three Doshas: Vata, Pitta and Kapha are three functionalities that regulate all physiological, psychological and spiritual facets of a person. Dosha can also be referred to as the biological type or the physical constitution. In Sanskrit, dosha is defined as “doshyati iti doshah”. This means “that which contaminates is called “doshah”. Imbalance of vata, pitta and kapha doshas cause disease in the body. Therefore, imbalance of these elemental combinations is the direct cause of an illness. The Vata or the air element governs inhalation, exhalation, movements, discharges, impulses and the human senses. The Pitta or the fire element deals with hunger, thirst, digestion, excretion, body warmth and circulation. It also relates to body strength, energy, youth intelligence and executive abilities. The Kapha or the water element controls the stability, lubrication, movements, body luster, digestive tract, glands and fluids of the body. Other factors such as imbalance or defect in the dhatus (body tissues), toxins, waste materials etc. are the result of imbalance in the doshas.

Digestive fire: Referred to as Agni, is a term representative of body metabolism, and comprises of digestion, absorption and assimilation. It is vital for turning assimilated food into Dhatus, like plasma, blood, muscle, bone and fat. The food is also broken down to form seminal fluid in men, Artava in women (English language does not have any term for Artava) and Ojas, and the vital force, in both. In Atharva Veda, these 7 dhatus/tissues have been referred to as the Sapta Matram (7 makers of the body).

Excretory functions: In Ayurveda, a lot of emphasis is laid upon excretory functions, as these are deemed vital for maintaining perfect health and keeping diseases at bay. It is said that proper excretory functions ensure good health & spirit and increases life span. Ayurveda describes the methods of maintaining the ideal lifestyle for people of all ages.

Pleasantly disposed contented spirit, senses and mind: Being holistic in nature, Ayurveda stresses upon the importance of social wellbeing, which can be achieved only when the spirit, senses and mind are content.

In conclusion, the Ayurveda is a science which has a holistic approach to promote mental and physical health (prevention and treatment both) and happiness, improved quality of life and longevity. The goal in Ayurveda is on the equilibrium of the primary humors. Digestion of food and desire for eating, having good sleep without nightmares with timely discharge of bodily waste and proper coordinated function of mind and intellect.

Disturbance in food intake, day-to-day living, lacking a disciplined life and improper conduct in thought, speech and action leads to a disturbed intellect and these factors then become the cause of an illness.

History of Ayurveda

In eastern philosophy, it has been well established that the Vedas are the sources of all knowledge. As per Vedic tradition, the Almighty handed over all knowledge in the form of Vedas at the inception of humanity and then it was propagated further by oral tradition and then at some point in history, it was recorded. There are 3 entities: God, soul and nature. In Vedas, the knowledge of God and soul always existed in its perfection and has never needed improvement. Knowledge of nature, however, has been given in the Vedas in a seed form only and has required further development and modifications all along. Such knowledge includes the knowledge of all sciences. Medical science is no exception. Actually, the Ayurveda has long been considered the 5th Veda or the Upveda of Atharva Veda. In fact, all 4 Vedas contain mantras which deal with health and wellbeing:

1. Rg Veda: There are mantras in this Veda which define the purpose of Ayurveda, qualities of the healer, uses of medications, various parts of the body, surgery, various natural treatments such as fire therapy, water therapy, wind therapy, sun therapy, hand-touch therapy and yajna therapy. References are also made to treatment of poisoning, parasitology, geriatrics and sleep disorders.

2. Yajur Veda: The mantras in this Veda deal with the qualities and actions of the Vaidya (physician), names of different medications, parts of the body, geriatrics, and other natural therapies as mentioned in Rg Veda.

3. Sam Veda: There is very little in Sam Veda about medicine. What is available relates to the qualities and attributes of the healer, few treatments, geriatrics, and how to be energetic.

4. Atharva Veda: This is the main basis of Ayurveda. The subjects relating to Ayurveda in this Veda are the qualities and actions of Vaidya, parts of body, science of longevity, how to be free of illness, urology, sexual dysfunction, parasitology and other infectious diseases, treatment of poisoning, natural therapies such as sun therapy, water therapy, use of certain poisons in treatment, use of animal products, surgery, etc.

After the Vedas, reference to the medical science is found first in the Brahman Literature. Brahman granths state that the illnesses are more prevalent during change of seasons. Therefore, doing Yajna 4 times a year (chaturmasa yajna) was prescribed to reduce such illnesses. Also the food ingested was changed based on the season. Subsequent literature is somewhat scratchy until the time of Aitareya Punarvasu. One of his students was Agnivesa and he wrote Agnivesa Samhita. It is on the basis of this scripture that Sage Charak wrote his book Charak Samhita. The last 17 chapters of Charak Samhita are additions by Dridhabala. This book deals with medicine. Similarly, name of Dhanvantari is prominent in the field of surgery or Shalya Chikitsa. This may have been the basis of the Sushrut Samhita, the main scripture in the field of Shalya Chikitsa in Ayurveda. The last chapter of this book may have been written by nagarjuna. Both Charak and Sushrut seem to have existed around the 6th century BC. Next in line was Vagbhata who probably existed in 2nd century AD. He summarized and assimilated the works of Charak and Sushrut in the form of his two books. These are Ashtanga Samgraha and Ashtanga Hridya. Some say that the author of these two was the same person, others feel that these two were two different people. These books are quite similar and divide the Ayurvedic science in to eight different parts. These 8 parts are general medicine, pediatrics, psychiatry, surgery, toxicology, geriatrics, sexual dysfunction, as well as eye, head and ENT. The word charak actually means the one who has travelled and learnt. The word Sushrut means the one who has heard well and learnt. The word Vagbhata means the one who is eloquent in communication. Sage Charak, Sushruta, and Vagbhata together have been correctly called the Brihat Trayi.

From 8th to 11th century A.D., there were also a series of scholars who did quality work in the field of Ayurveda. These academics are Madhavakara who wrote Madhav Nidan, Bhavmisra who wrote Bhava Prakash and Sarngadhara, who wrote Sarngadhara Samhita. These three scholars together have been labeled as Laghu Trayi, or the lesser threes. For the next several centuries, very little progress took place in the field of Ayurvedic medicine as India endured through a multitude of invasions by many foreign forces. However, most of what is available today comes from the original texts and that which is new is simply a revival of the original. There has been some research of late, and there are over one hundred Ayurvedic medical schools in India and a few Ayurvedic research institutes as well. Modern medicine was almost nonexistent 400 yrs. ago. There was a statement by Moliere in 17th century that “physicians are people who poured medicines of which they knew little into the bodies of which they knew less.” Today we are all impressed and dependent on modern medicine for our medical care. Parallel development has not occurred in Ayurveda. Actually the basic approach to health is quite different in Ayurveda. The details are as follows:

There are 8 Parts/specialties of Ayurveda

1. General or Internal Medicine(Kaya Chikitsa) This deals with general ailments impaired by digestion and metabolism. "Kaya" means digestive fire (agni) and is responsible for digestion and metabolism. From an Ayurvedic perspective, when the digestive fire is not functioning properly, it causes diseases. Several infectious diseases are described in Ayurveda and are supposed to be the result of improper digestive function.

2. Surgery (Shalya Tantra): The original text of Sushruta Samhita lists approximately 101 surgical instruments. Some surgical procedures included in this book are rhinoplasty, cataract and C. section.

3. Pediatrics (Kumara Brutya) This branch deals with prenatal and postnatal baby care as well as the care of a mother before, during and after pregnancy. It also elaborates various diseases of children and their treatments.

4. Psychiatry (Graha Chikitsa ) This branch deals with the study of mental diseases and their treatments. Treatment methods include medicines, diet regulation and yogic methods for treatment of mental diseases and improving mental balance and wellbeing.

5. Shalakya Tantra (ENT and Ophthalmology) This branch focuses on the areas of the body above the collar bones. These include ear, nose, throat and head and their treatments and cure. This branch also includes dentistry.

6. Agadatantra (Toxicology) This branch deals with the toxins derived from vegetables, minerals and from animal origins as well as how to process and remove them. The concept of pollution of air and water in certain places and seasons has been given special consideration. Such pollution is also said to be the cause of various epidemics. It also discusses the proper storage of food etc.

7. Science of Rejuvenation (Rasayana). This branch which is unique to Ayurveda, focuses on general health and vitality including care for the elderly. Its main aim is to promote healthy living, with emphasis on both the prevention and cure of diseases. It deals with the promotion of a long and healthy life and discusses how to improve our health, intellect and beauty.

8. Virilisation Therapy (Vajeekarna): This deals with the science of sexual dysfunction and its prevention and treatment.

Detailed references about medical science in the Vedas

I must state that when we compare knowledge of anatomy, physiology, pathophysiology and treatment of various illnesses as we see these in modern medicine, there appear to be many inconsistencies in knowledge in Ayurveda. However, I will simply state the references in the Vedas as they appear.

In Atharva Veda(A.V.), 42 parts of body have been described and 36 qualities of mind have been described. Ref: AV 10.2.9/10/17, 11.8.19-27
Sushrut has described that heart has the shape of upside down lotus. He also mentioned that it contracts, relaxes and slows down when we sleep.
Atharva Veda described that Vata, Pitta and Kapha exist as a form of vital energy in the body. Pitta has been described as fire A.V. 18.3.5.
5 types of Vata (vayu) prana, apan, vyan, saman and udan have been mentioned in A.V.9.8.20.,6.109.3,6.44.3

Kapha has been called Somavat (calm). A.V. 1.12.3.,6.14.1.,8.7.10.

Arteries, Veins, nerves have been described in A.V. 1.17.2/3,7.35.2 in reference to trauma, where efforts/prayers are made for stopping of bleeding and closure of wound with closure/rejoining of the nerves and vessels. There are many references in Ramayana and Mahabharata about taking care of wounds of those injured in war. Sushrut has described 700 veins, 24 arteries, 500 muscles, 900 ligaments, 300 bones and 210 joints. Small intestine has been described as 22 ft. and the colon as 5 ft in length.

Sushrut has described 7 layers/coverings of Skin. The first layer is visible and gives us the color of skin and other deeper layers have been described from which various diseases such as skin abscesses, anal fistula/abscesses etc. originate. According to Charak, there are 6 layers. The first one has water, next has blood, next the origin of leprosy and vitiligo, next ring worm, next furuncles and abscesses etc. Modern medicine describes 2 layers, the outer Epidermis with 5 layers and the deeper Dermis with 2 layers.

107 vital parts have been described in A.V. 7.118.1. The concept of vital parts here is different here than in modern medicine. These should actually be called important parts. It has been described that a person dies if injury to these parts occurs. Here God describes in first person that I protect your vital parts/organs of body and also a prayer has been done for protection of vital parts and long life. Here vital parts include those needed for basic quality of life, such as hands, feet, fingers, toes, organs of defecation and urination, back, hips, head, neck and breasts. Internal organs such as heart, lungs and brain have been included as well.

Seminal Fluid: Acording to Sushrut, seminal fluid pervades in the entire body and then collects in testicles to be ejaculated.

The word Nidan mainlymeans the main cause of a particular illness. Means to arrive at a diagnosis and treatment are also called Nidan.

Vata, Pitta and kapha have been considered as the main reason for any disease. Inappropriate and irregularity in food intake or ingestion/inhalation/injection of any undesired substance has been the labeled as the reason for disturbance in the balance of the 3 doshas. Disturbance in daily routine such as sleep, meals, stress lead to illnesses A.V. 1.12.3.

Vedic teachings state that “the illnesses are based on Poisoning, infection and disturbances in Doshas”. Poison can gain access to our bodies through injection, ingestion, poisonous animal bite etc. A.V. 9.8.10. It is also mentioned that only poison can cure the poisoning A.V. 5.13.4. Infectious organisms have been described as visible and invisible A.V. 5.13.4. They exist everywhere and gain access to our body and causes illness. It is quite amazing that both bad and good bacteria have been described. Today, probiotics are used extensively and more and more studies are proving the usefulness of probiotics. Many diseases caused by different types of infectious organisms have been described. Vedas describe the diseases to be both mental and physical. Excessive lust and ill thoughts are considered serious reasons for illnesses as well.

Rg Veda describes 3 types of medications: divine, earthly and watery. Pranayama has been given considerable importance in disease management. Eating small, wholesome and timely meals as well as avoidance of constipation have been considered quite important. Good thoughts, purification of mind, being peaceful, use of appropriate medications and doing Yajna on a regular basis have been considered the main way to manage diseases.

Different fevers have been described. These could be with chills, simply high fever or cough predominance. Change of seasons brings fevers. Again, irregularity in routine and uncleanliness and obesity have been described as the reasons for fever. AV 5.22.5 states that being in place with more precipitation, forest and lack of sunshine increases the chance of fever.

In summary, on one hand Ayurvedic concepts, even though they have existed for thousands of years, seem very modern when we talk about basic principles of living and life style modification as the main stay of management of illnesses. There is absolutely no question that the benefits of Yogic practice with emphasis on Pranayama and meditation exceed any comparative item that modern medicine has to offer. On the other hand modern medicine has gone ahead by leaps and bounds in management of specific diseases and is and will remain the main stay of treatment of most illnesses. However, research in Ayurvedic medications may produce some gems and should be perused.