Visha or poison is a substance capable of causing disease or death. According to Ayurveda, the word Visha is etymologically derived as ‘Vishadam jayayati iti visha’, which means ‘that which produces misery or sorrow is termed Visha.’ In broader sense, Visha is a substance which, when in contact with the human system either internally or externally, produces instantaneous or delayed physiological reaction and causes diseases or even death.
Visha can be broadly classified into two types, namely, kritrima and akritrima. Kritrima type is the unnatural or the synthetic type of poison and is also termed samyoga visha and is similar to that of ama dosha. This type is further divided into two, namely savisha and savisavisha. The savisha is poison, which is produced by the combination of toxic substance in small quantities and does not produce toxic effect instantaneously. They cast their influence on the body when the conditions are favorable and are also termed dushi visha.
Savisavisha type is also termed gara visha and is produced by the combination of non-poisonous substances, which in combination produce a toxic effect over the course of time.
In Ashtanga Samgraha, it is mentioned that for the sake of material gains, sovbhagyartham, people may combine certain special substances, which are of vegetable, animal and mineral origin, and give it to their spouses or any other person in order to influence them psychologically.
Sthavara visha or visha of plant origin has adhogati (a downward movement) – they have prithvi and jala mahabhuta predominant whereas visha of animal of jangama orgin possess urdhvabati upward movement, i.e. they are agni mahabhuta predominant. This concept has an implication in the therapeutic aspect since they counteract each other’s effects.
If an individual consumes or comes in contact with poison either by stings, bites, etc., the poison vitiates the blood initially, and by spreading to all parts of the body along with the blood it vitiates the other body tissues and the doshas, affects important marmas such as the hridaya (heart) and deranges the ojas (vitality) situated in the heart by blocking the channels and affects the prana or the life force thereby causing death. The qualities of visha (poison) are diametrically opposite to the qualities of ojas (vitality), which is responsible for the sustenance of life.