This is the most fundamental principle of ayurveda .While the theory of five elements helps us to understand the universe ,the concept of the three doshas helps us to understand the human body . Its gives us a better understandig of our biological nature .If the five elements of air , fire ,water ,space and earth are the basic elements of the universe , three doshas are the basic biological molecules which constitute all living creatures from microbe to human .
Vatta, pitta and kapha together form the three doshas. Ether and air together constitute VATA; fire and water, PITTA and water and earth KAPHA; VATTA, PITTA and KAPHA present in every organelle of the cells.

These three doshas form the basis of your physical and mental constitution. Every indivisual is made up of three doshas in different
Combination and permutation that determine the physiological and mental constitution of the individual.

Vatta :-
The air or nervous system, vata is the predominant of all the three doshas and has movements in all direction .It is responsible for the circulation of the blood and body fluid, and also circulates pitta and kapha throughout our bodies. Principle function of vata is to sustain and support life. That’s why vayu is reffered as prana. There are five type of Vata and following are the important functions of each type of vata;

• Prana Vata: It control the activity of mind, brain, all senses regulates salivation, sneezing, hiccup, respiration and mastication.
• Udana Vata: Regulates generation of voice, memory, energy and power.
• Samana Vata: It supervise the movement of food in the GIT .It controll –digestion, metabolism, absorption. Also differentiate food in to absorable and excretable end products.
• Apana Vata : Elimination of wastes, sexual function, menstrual cycle
• Vyana Vata: Contoll blood flow, heart rhythm, perspiration, movement opening and closing of eyes.

Pitta :–
The principle function of pitta is to maintain the body by supplying and producing heat. This is why the fire is considered the dominat element of the pitta. There are five type of pitta and following are the important functions of each type of pitta.

Pitta -Types and their Functions:
• Pachaka Pitta : Responsible for digestion, assimilation, metabolism for healthy nutrients and tissues
• Ranjaka Pitta : It provide colouration to the blood . It regulate the function of the liver and spleen and responsible for healthy, toxin-free blood
• Sadhaka Pitta : Controls desire, mind, decisiveness, spirituality
• Alochaka Pitta : Controls functioning of the eyes
• Bhrajaka Pitta : Responsible for colouration of the skin

Kapha :–
The main function of kapha is to form and preserve the body by acting as the body’s wartery subastance. There are five type of kapha and following are the functions of each type of kapha.

Kapha - Types and their Functions:
• Tarpaka Kapha : Responsible for moisture for nose, ear, mouth, eyes and brain
• Bhodaka Kapha : Governs Sense of taste,
• Kledaka Kapha : Controls moisture of the stomach and intestinal mucosal lining . And protect the GIT from wear and tear process.
• Avalambaka Kapha : Protects the heart, lung , strong muscles etc .
• Sleshaka Kapha : Lubricates the joints,Keeps skin soft and supple.