Guna are three in number as described by ‘samkhya darshan’. These are: sattva, rajas and tamas.
Sattva guna: - sattva guna is buoyant, lightened and depicts contentment. It fastens any action and therefore is also termed as accelerator in nature. It aids in realisation of knowledge and physical senses. Mind, wisdom, enlightenment are its attributes only. Buoyancy is its main characteristic. It leads to a feeling of free flowing and raises one above the worldly chores. As a result, all forms of contentment, happiness, fulfilment and pleasure are abundant in sattva guna. It is mainly expressed by white colour.
Rajas guna: - rajas guna symbolises the motion. It is the main factor behind creation of any and all actions. Sattva and tamas guna are themselves unable to execute their functions without the help of rajas guna. All kinds of actions in nature are considered to be due to rajas guna only. That is why; it is also called as the initiator in nature. Rajas guna is responsible behind all the feelings of suffering, misery and all other kinds of physical and mental tension. Rajas guna is expressed in red colour.
Tamas guna: - tamas guna symbolises the obstruction and is heavy in nature. It drags everything down wards only, which can be termed as gravity. This characteristic is an absolute opposite to the buoyant trait of sattva guna. It obstructs the light and can also be defined as inertia. Due to this factor it tends to stop everything in motion, from the very tiny cell to gross cosmic creation. It envelops wisdom and thence hinders knowledge. It leads to darkness and is represented by black colour.
The relevance of these three gunas is comprehensible and applicable in medical science. As, these gunas are present in individuals and are expressed in the dominant form only. A sattva guna individual will have a calm, tranquil and meditative mindset. Rajas guna individual will be active but very much encored in worldly pleasures and may show aggression in behaviour. Tamas guna dominant individual may exhibit traits like lethargy, depression, and a basic inactivity in behaviour.
These three guna are characteristically different from each other but they work in unison. They are the basics of human existence as well as the whole universe and lifecycle in a larger perspective.
To simplify, Sattva guna is accelerator, rajas guna is the initiator, and tamas guna is the obstructer or destructor. All of the three functions are important and necessary to strike a balance in nature.