Ayurveda has continued to be used for over 50 centuries because it does not simply treat the disease but adopts a holistic approach to the patient. The ailment is related to his/her life style and both mental and physical health are taken care of. Since it is a natural therapy with medicines being prepared from herbs and minerals after proper processing, there are no side-effects or complications.

Ayurveda is based on the philosophy of Sankhaya which believes that there is a state of pure existence or awareness, without end and beyond time and space, behind all of creation. If there is a lack of equilibrium in this state, it leads to the manifestation of primordial energy, which in turn leads to creation. This primordial force is the creative force behind every action so that matter and energy become virtually interchangeable.
 
Ayurveda also believes in a cosmic consciousness which encompasses individual intelligence. This leads to the concept of Ahamkara, often mistaken for ego. Ahamkara is that part of the individual consciousness which can recognise its part in the universal creation. From Ahamkara rises a two-fold creation: the Satva or the subjective world which can perceive and manipulate matter and Tamas or the objective world of the five elements of sound, touch, vision, taste and smell. Satva comprises the mind and the capacity of the sense organs to hear, feel, see, taste and smell and the five organs of action to speak, grasp, move, procreate and excrete. Tamas comprises the subtle elements which give rise to the dense elements of ether or space, air, fire, water and earth from which the entire physical world is derived. Rajas, the force or the energy of movement brings together parts of these worlds. Thus are the spiritual and physical worlds interconnected.

A basic premise of Ayurveda is that human life is a co-ordination of the atma or soul, the mana or mind, the indriya or senses and the sharira or body. These with the five dense elements go into the making of the prakriti or constitution of the individual. Prakriti is in turn determined by the vital balance of the three physical energies called vata, pitta and kapha and the three mental energies, the satva, tamas and rajas. Thus Ayurveda deals with aspects of existence beyond the physical world. It is not simply a health care system but a form of lifestyle adopted to maintain perfect balance and harmony within the human existence.

Ayurveda has eight specialized branches. They are as follows :

Ayurveda was propounded and practised by the rishis, or spiritual teachers, of ancient times who spent long periods in isolated study and meditation. The main source of knowledge of this system are the Vedas, especially the fourth or Atharvaveda which dates back to 1000 BC. A few other treatises dating to the same period are the Charaka Samhita on internal medicine and the Sushruta Samhita on surgery. About a thousand years ago, the gist of these older texts was compiled and called the Astanga Hridayam. These remain the core of Ayurveda as it is practised even today.

Ayurveda was not confined to India alone. Around the 6th century BC, Buddhist monks travelling to Tibet, China, Mongolia, Korea and Sri Lanka carried the knowledge with them. Although it has not survived in its original form, some of the new age concepts that have emerged from that part of the world can be traced back to this ancient system.

Ayurveda is based on the premise that when an abstract spirit desires to express itself, it uses satva or subjective consciousness to manifest sense organs and a mind which are then projected into a physical body formed by the panchamahabhutas which arise from tamas, the subtle world. The sense organs then use rajas to enable the spirit to achieve its objective. The body thus becomes a physical instrument of the mind.

According to Ayurvedic principles, the three gunas or psychic forces - rajas or activity, tamas or inertia and satva which balances the former two - determine our mental and spiritual health. It is only by balancing these energies that optimum health and well being can be attained.

Panchamahabhutas

The panchmahabhutas or the five great eternal elements are

According to Ayurveda, everything, both animate and inanimate, is composed of an infinite variety of these panchamahabhutas in relative proportions. Constantly changing and interacting with each other, each element has distinct attributes and together they create a situation of dynamic flux.
The panchmahabhutas are significant because they serve as the foundation of all diagnosis and treatment.

Agni
Of the panchmahabhutas, agni deserves special mention because, according to Ayurvedic principles, agni governs the entire sequence of chemical interactions in the body and is, quite literally, the fire of metabolism. It is said to control even changes in the mind.

Tridoshas
From the panchmahabhutas arise the tridoshas or the three (tri) basic physical energies (doshas) which govern our physiological and psychological processes called vata, pitta and kapha. Each dosha, which literally means that which maintains and controls the body, is a combination of two of the five bhutas, of which one is dominant. According to Ayurveda, every physical characteristic, mental capacity and emotional tendency of an individual can be attributed to a dosha. And it is when an imbalance is caused in the doshas that disease is caused.

Trigunas
The trigunas - satva, rajas and tamas - are the three (tri) energies of the mind. In Ayurveda, people are distinguished on the basis of their manasa (psychological) prakriti (constitution). Although genetically determined, prakriti is dependent on the relative dominance of the three gunas. Again, when in equilibrium, the gunas maintain a healthy mind, and therefore a healthy body. A disturbance in this state causes various types of mental disorders.

Saptadhatus
The sapta (seven) dhatus (tissues) are termed the pillars of the body in ayurveda. They are:

These tissues are interdependent and also governed by the doshas. Any imbalance in them also causes an imbalance in the dhatus.

Malas
The malas are the waste products of the dhatus produced by the metabolical process. The three primary malas are:

According to Ayurvedic principles, a balanced condition of the doshas, dhatus and malas is arogya, that is, a disease-free and healthy condition and it is only an imbalance of these which causes ill-health or disease.

Prakriti
The Prakriti or basic constitutional nature of each individual is determined by the permutations and combinations of the sukra and arthava or male and female gametes of the parents, which in turn are made up of the five dhatus, at the time of conception. Ayurvedic principles indicate that despite the influence of culture, society and environment, our basic nature at birth is established by the combination of the dhatus and remains constant.