Ayurveda is a science based on detailed theories and principles. These theories explain evolution and define the environment, human beings, and how they relate to each other. The main principles are:
Three primordial forces (Triguna):
The three forces (gunas) represent the phases of creation, as well as the qualities of the mind. Everything in the universe is influenced by the triguna (sattva, rajas and tamas). In the theory of evolution, sattva brings into creation and is pure consciousness, rajas is a maintaining and moving force and tamas represents the cohesive unity or destructive force. In the human mind, sattva is purity or goodness, rajas is action and passion, and tamas is ignorance or darkness.
Five Elements (Pancha Mahabhuta):
The universe is composed of five elements. Everything in the universe, including human beings, are made up of different combinations of the same five elements. These elements are earth (prithvi), water (apa or jala), fire (tejas or agni), air (vayu) and space (akash).
Three biological forces (Tridosa):
In humans, the five elements combine to produce three primary life forces, or three "biological humors". The Ayurvedic term for this is dosa. As there are three, they are referred to as the tridosa (tri meaning three).
The three dosas are vata, pitta and kapha. Each dosa is made of the five elements, however each has a predominance of one or more elements. Vata has a predominance of the elements of air and space and is responsible for movement, Pitta has fire as the dominant element and controls transformation, and Kapha has predominance of water and earth and represents cohesion.
All humans have the three dosa present in different proportions. This unique combination of tridosa is responsible for our unique natures. Knowing your constitution assists both in preventing as well as curing the diseases. (see fact sheet on constitution for more information).
Ayurveda has a distinctive concept of how the human body is structured and functions. Very important aspects of health include digestion and accumulation of wastes. The digestive system is considered the key to good health. It is called jatharagni, meaning digestive fire. The state of agni determines how well food is assimilated into the body.
If agni is weak, if too much food is consumed, or if food is eaten at an inappropriate time, it cannot be digested adequately. Rather than nourish the body, the food is transformed instead into a toxic residue known as ama. The waste (ama) circulates around the body and ultimately creates disease (imbalance).
The basic tissues which maintain the body are known as dhatus. There are seven dhatus - plasma, blood, muscle, fat, bone, marrow and reproductive fluid. The quality and quantity of each dhatu, and its balanced functioning, is another important factor for good health.
Mala are the waste materials produced as a result of various metabolic activities in the body. The main mala are urine, feces and sweat. Proper elimination of mala is equally important for good health. Accumulation of mala causes blockages in the body which result in manifestation of various diseases.
There are also invisible aspects to the human body, such as marmas (sensitive points), cakras (energy centers), nadis (energy channels) and prana (life air). This is more advanced theory relating to the subtle body.