Gunas

Guna is defined as the characteristic such as the quality, mode, physical property or predicament of a particular substance.

Charaka defined guna as a character or property which remains in a dravya (drug) as an inherent relationship.

We understand various materials only because of their properties or qualities (gunas) as these impress us through our senses. The qualities of compounds reflect those of molecules. The qualities of molecules are determined not only by of the atoms that compose them but also the manner or mode in which they combine in substances. Their qualities are mutually determining. In other words, the qualities implicit in the elemental substance which are designated as the karma or cause, become actualised in the effect. The basic principle is the the properties that exist in the causative factor are seen to manifest in the resultant factor Sastry Dr.J.L.N "Dravyagunna Vijnana (Fundamental Principles of Phamacotherapeutics in Ayurveda, Varanasi: Chaukhambha Orientalia, 2004}}.

Gunas

There are 20 gunas arranged in 10 pairs. Each pair consists of two gunas with opposite qualities:

Guru	Laghu
Sheeta	Ushna
Snighda	Ruksha
Manda	Tikshna
Stira	Sara
Mridu	Katina
Visada	Pichchila
Slakshna	Khara
Sthula	Shukshma
Sandra	Drava

Guru

Generally means heavy. It is the quality which is responsible for the force of gravity. Mass and gravitational forces are directly proportional. Guru gunas act action reduces Vata and aggravates Kapha. It nourishes all the dhatus (Brimhana); it increases malas and coats the srotas.

On the Psyche (manas) it may impose inhibitory effects on receptive capacity.

Laghu

This is the quality that is of very light weight or that which reduces weight. It is a substance that posses lower molecular weight. It reduces Kapha and aggravates Vata; reduces tissue weight (Langhana); reduces malas and clears the channels of the body. It improves the digestion because it is easy digestible.

On the psyche (manas) if has a positive effect by improving activeness and providing inspiration.

Sheeta

A quality the reduces body temperature is called Sheeta. It helps to check the flow of water and fluids. Sheeta subsides Pitta and aggravates Vata and Kapha; improves tissues; acts as a diuretic and controls sweating and purgation. It produces a pleasant mental state.

Ushna

A quality that increases the body temperature or which causes sweating. It reduces Vata and Kapha and increases Pitta. It results in haemorrhage and has adverse effects on dhatus; it reduces the quality of urine and increases that of sweet and stools.

Snigdha

A quality which provides oily or unctuousness. It will provide smoothness, moisture and an oily nature to the body. It reduces Vata and aggravates Kapha; provides tonicity to tissues; regularises the movement of malas and acts as a Vajikarana.

Ruksha

A quality that increases dryness in the body or which results in absorption of moisture. It reduces Kapha and aggravates Vata; it will have a reducing effect on the dhatus reduces the quantity of excreta.

Manda

A quality that is responsible for slow activity or delayed response (dullness or mildness). It will subside the vitiated doshas and is helpful in palliative treatment of diseases. This quality causes drug to travel slowly through the body. It aggravates Kapha and reduces Vata; it strengthens the tissues and does not help in the expulsion of excreta.

Tikshna

The quality of sharpness or fast-acting. It is responsible for the quick activity or sharpness of a drug. It is known as the property which will expel the doshas completely i.e., it is helpful in the curative treatment of diseases. This property usually stimulates through irritation. It increases Pitta and reduces Vata and Kapha; it enhances the excretion of malas

Sthira

The quality which brings about immobility or firmness. It provides strength to many of the body tissues and skin appendages such as hair, teeth, bones etc. It increased Kapha and reduces Vata; strengthens all the dhatus; controls feces and flatulence.

Sara

The quality of mobility. It is a substance which spreads very easily and quickly all over the body. It is the property that stimulates movement. It aggravates Vata it reduces tissue weight and enhances the movement of malas.

Mridu

A property which brings softness and fragility to the body. It aggravates Kapha and reduces Vata - Pitta and brings about the fragility to the tissue; liquefies the excreta. It is useful in reducing burning, inflammation and secretions.

Katina

Gives rise to hardness and rigidity. It aggravates Vata, provides hardness and strength to the dhatus. It dries up excreta.

Visada

It provides a transparent nature or clearness to the subjects. This quality provides clean and clear state to the tissues. It clears the dhatus of impurities. It aggravates Vata and reduces Kapha.

Pichchila

A quality which brings stickiness. It has a coating effect on the tissues, aggravating Kapha and reducing Vata; it improves the dhatus and gives excreta a stickiness.

Slakshna

A quality which gives smoothness. It helps in the soothing process. It acts as a Kapha – Pitta vardhaka and reduces Vata; causes expulsion of the [[malas].

Khara

The quality of roughness. It has a lakhana property, it reduces the dhatus and the quantity of the malas.

Sukshma

The quality of fineness or microscopic nature. It is the quality which a drug can penetrate through the minutes channels of the body. It is defined as the fineness of a substance. It aggravates [[Vata] and reduces Kapha; reduces tissue weight; and reduces the quantity of excreta.

Sthula

The quality that brings bulkiness and delay in disintegration of a drug. It results in the obstruction to the channels of the body. It to aggravate Kapha and reduces Vata – Pitta. It increases tissue weight and the quantity of malas thereby helping in expulsion.

Sandra

The quality of solidity or turbidity. It is describes as the property by which different parts of the body are strengthened or nourished. It aggravates Kapha and reduces Vata increases the tissue functions and structure; solidifies the excreta.

The property of fluidity. It aggrivates Kapha and Pitta and reduces Vata; it improves the liquid dhatus such as Rasa, Rakta etc/; it also increases the quantity of excreta.