The most fundamental and characteristic principle of Ayurveda is called "Tridosha" or the Three Humors.
All matter is thought to he composed of five basic elements ( panchamahabhutas ) which exhibit the properties of earth (prithvi), water (jala), fire (tejas), wind (vayu) and space (akasha).
The structural aspect of our body is made up of five elements, but the functional aspect of the body is governed by three biological humors. Ether and air together constitute VATA; fire and water,PITTA; and water and earth, KAPHA. They govern psycho-biological changes in the body and physio-pathological changes too. Vata-pitta-kapha are present in every cell, tissue and organ.
Doshas are to be seen as all pervasive, subtle entities, Vata regulates movement and is represented by the nervous system. Pitta is the principle of bio transformation and is the cause of all metabolic processes in the body. Kapha is the principle of cohesion and functions through the body fluids. In every person these three doshas differ in permutations and combinations and thereby determine the physiologic constitution (Prakriti) of an individual. Vata, pitta and kapha are distinctly present in every individual and express in each human being differently according to predominance of their different qualities (gunas).

VATA - The Air or Nerve System Humor
vata is dry, light, cold, mobile, active, clear, astringent, and it is dispersing. Vata season is autumn, time of day is afternoon and early morning.
VATA -Types and their Functions:
Vatadosha is further divided into 5 types according to it's seat and the different functions it carries
• Prana Vata : Governs the senses, creative thinking, reasoning, enthusiasm,
• Udana Vata : Governs quality of voice, memory, movements of thought
• Samana Vata : Governs movement of food through digestive tract
• Apana Vata : Elimination of wastes, sexual function, menstrual cycle
• Vyana Vata : Governs blood flow, heart rhythm, perspiration, sense of touch
Useful Tips to Balance Vatadosha

DO's:
• Abhyanga (ayurvedic massage with sesame oil)
• Stay warm in cold, windy weather
• Consume warm, cooked foods (less raw foods)
• Go to bed early have lot of rest and sleep.
• Favour warm, oily, heavy food with sweet, sour, and salty tastes.

DON'Ts:
• Avoid light, dry, cold, pungent, bitter and astringent foods
• Avoid raw foods, juices, fasting
• Avoid stimulants ,smoking ,alcohol
• Refrain from excessive aerobic activity

Medication for Vata
Medicines and herbs that are demulcent, emollient, warmly diaphoretic, nerviness, antispasmodic, warming and carminative are appropriate for treating Air imbalances. They are also particularly amenable to the internal and external application of herbal medicated oils. Castor oil because of its thick viscosity, is considered the strongest oil for treating excess vata conditions. Herbs and substances that are bitter and astringent such as cascara bark and bayberry bark, increase Air, while those that are sweet and demulcent, such as slippery elm, marshmallow root and comfrey, ameliorate it. The primary Panchkarma therapy for vata derangement is the use of medicated oils usually applied externally.

PITTA - The Fire Humor
Pitta has hot, sharp, light, liquid, sour, oily and spreading qualities. Pitta has a strong smell, like a fleshy smell, and has a sour or bitter taste.
Pitta -Types and their Functions
• Alochaka Pitta : Controls functioning of the eyes
• Bhrajaka Pitta : Responsible for healthy glow of the skin
• Sadhaka Pitta : Controls desire, drive, decisiveness, spirituality
• Pachaka Pitta : Responsible for digestion, assimilation, metabolism for healthy nutrients and tissues
• Ranjaka Pitta : Responsible for healthy, toxin-free blood
Useful Tips to Balance Pitta dosha

DO's:
• Keep cool. Avoid hot temperatures and hot food
• Favor cool, heavy, dry, sweet, bitter and astringent foods
• Keep activities in Moderation.
• Keep regular mealtimes, especially at noon

DON'Ts
• Avoid sesame and mustard oils, fish, buttermilk, mutton, acidic fruits, alcohol, meat and fatty, oily foods.
• Restrict pungent, sour, salty, warm, oily and light foods
• Avoid over work
• Avoid fasting

Medication for Pitta
Medicines and herbs that are cooling, purging, laxative, antipyretic and blood detoxifying, cholagogic (releasing bile) are appropriate for treating Fire imbalances. Laxative herbs such as cascara bark, rhubarb and senna are used to clear excess Fire. When there is no constipation, one can use alterative or cholagogic herbs such as red clover, sarsaparilla, oregon grape root, barberry root and dandelion root. The major Panchkarma therapy for excess Fire is bleeding. Generally such patients who are not predisposed to anemia should make it a point to regularly donate blood at a local blood bank.

KAPHA -The Water Humor
Heavy, slow, cool, oily, liquid, dense, thick, static and cloudy qualities. These are the important qualities of kapha, and kapha is sweet and salty.
Kapha - Types and their Functions :
• Tarpaka Kapha : Responsible for moisture for nose, mouth, eyes and brain
• Bhodaka Kapha : Governs Sense of taste, which is essential for good digestion
• Kledaka Kapha : Controls moisture of the stomach and intestinal mucosal lining
• Avalambaka Kapha : Protects the heart, strong muscles, healthy lungs
• Sleshaka Kapha : Lubricates the joints,Keeps skin soft and supple.
Useful Tips to Balance Kapha

DO's
• Do regular exercise, Begin with Sooryanamaskara to warm up your body, which should be followed by a Vigorous activity
• Prefer warm temperatures, Stay warm and dry in cold, damp weather
• Use Fresh fruits, vegetables and legumes
• Favor pungent, bitter, astringent, light, dry and warm foods

DON'Ts
• Reduce heavy, oily, cold, sweet, sour and salty foods
• Avoid heavy meals.
• Sleep promotes Kapha hence avoid excessive sleep,
• All frozen desserts are to be avoided.

Medication for Kapha
Medicines and herbs that are diuretic, warming diaphoretic, warming stimulant, expectorant, carminative and aperient (mildly laxative) are appropriate for treating Kapha imbalances.