Vata is one among the three doshas (humors) which support the body. The term Vata is derived from the root “Va” meaning to move, to enthuse, to make known, to become aware of and to enlighten. Vata is responsible for conducting both motor and sensory functions, therefore the term Vata is very suitable name.
 Although all the three somatic humors are equally important Vata appears to be the primary motive force. It is a fact that movement in the corporeal body is indicative of the presence of life. The cause of such movement is Vata. Vata is considered powerful and important because of its control over the functions of the body, swift action, strength, capacity to vitiate other factors, independent movement and the large number of diseases produced due to its vitiation.
It is stated that Vata is Panchabhautika (five matters) with the predominance of Akasha (space) and Vayu (air) bhutas. According to Charaka the qualities of Vata are ruksha (dryness), laghu (lightness), sita (coldness), daruna (motility), khara (roughness), visada (clearness), sukshma (penetrative) and chalatva (mobility).
The qualities of vata appear to be based on inferential reasoning. Both Lokavayu (physical vata) and sarira vata (biological Vata, the somatic humor) are invisible. Therefore the presence of both can be recognized by the functions they perform. Another important observation for the inference of the qualities of the Vata, is related to the influence of food, medicine and activities. It is also stated that Vata is Yogavahi, viz. a medium which when associated with other substances projects their qualities, without losing its own qualities. When Vata induces the other two humors into activity, it identifies itself with them; when associated with Pitta produced a feeling of hotness and when associated with Kapha produces a feeling of coldness.
The seats of Vata are Vasthi (urinary bladder), Purishadhana (rectum and Large intestine), Pakvasaya (intestines), Kati (Pelvis or Hips), thighs, feet and bones. Additional locations of the Vata are the ears and the skin. It is a fact that the perception by those two sensory organs is mediated through changes in the air currents. In addition to this Siras (Head) also has to be considered the seat of Vata and is responsible for the motor and sensory functions.
The functions of the humors are of two types: physiological functions conducted in their state of equilibrium and abnormal functions conducted by the vitiated humor. The physiological functions of vata are as follows:
1. Vata is the upholder of both structures and function in the body.
2. It is the originator of every kind of action in the body.
3. It is the controller and conductor of the mind.
4. It stimulates all senses of the body and conveys all sense stimuli.
5. It plans the regular synthesis of the Dhatus (which supports the body) and joins the dhatus in a proper proportion to form the structure of the body.
6. It is the generator of the speech, touch, sound and hearing.
7. It is the origin of all excitement and animation.
8. It stimulates the digestive fire.
9. It is the eliminator of the excretions from the body.
10. It is the decisive factor of the developing of all Srotas (channels) of the body.
11. It is the cause of formation of different structures of the foetal body.  
12. The action of the involuntary muscles like heart, the intestines and also the respiratory functions which are both voluntary and involuntary.
13. The action of the skeletal muscles.
 The five divisions of Vata are Prana Vata, Udana Vata, Samana Vata, Vyana Vata and Apana vata. Of these five Prana Vata is the only one which is considered as the life of the human being.
         The word Prana means to live, to breathe. In view of this definition, the Prana Vata should be responsible for all vital function like respiration, heart rate and other vegetative functions, which are essential for human existence. Prana Vata is situated in the shiras (head). Prana Vata is stated to transverse in the regions of oral cavity, ears, neck and chest for the proper control and discharge of its functions. Functions of Prana Vata are respiration, deglutition, spitting out, sneezing and belching. It maintains the actions of heart and circulatory system, mind, intelligence, sense organ and support the vasomotor functions.
           Udana vata is considered to be responsible for the strength of a person. The seat of Udana Vata are umbilicus, chest and throat. The functions are verbal expression, effort, enthusiasm, vitality and complexion.
The Vyana Vata is in control of the voluntary movements of the body. It is located in heart but transverse throughout the body very swiftly. The functions are motion, extension, contraction, winking of the eye, the regulation of the circulation, outflow of sweat and blood from the body, flexion, lateral thrust, yawning, recognizing the taste of food, cleansing of channels, depositing the semen inside the vaginal cavity and separating the essence of food from the waste matter and nourishing the dhatus.
The digestion of food and separation of essence from the waste are conducted with the help of Samana Vata. It is seated in the intestine and helps stimulation of digestive juices and control movement of the intestine.
Apana Vata is situated towards the lower part of the body, urinary bladder, penis, rectum and lower limbs. It facilitates excretion, menstrual flow, semen ejaculation and delivery of foetus.