The doshas have certain qualities or attributes, which characterize their effects on the human body. The individual remains healthy as long as these elements are in state of equilibrium in the body. The body has the capacity to overcome minor disturbances in their equilibrium. But if this equilibrium is disturbed beyond a point, the body succumbs to disease and decay. The doshas exist in two forms of the body, namely, gross and subtle. In their subtle state, they are beyond the normal cognition of the senses.

Their normal and abnormal states are ascertained by the manifestations of their respective actions. These three doshas control all the physical and psychological functions of an individual. Each one of these doshas is further subdivided into five categories on the basis of their actions on different parts of the body. The details of the actions of the three doshas can be found in Ayurvedic texts. They are briefly stated here.

Vayu or vata is unctuous, light, cold, mobile, abundant in quantity. It is the originator of all movement in the body and it governs, in general, all nervous functions. There are in all eighty kinds of possible disturbances that can occur due to vayu imbalance. Some of these are pain, stiffness, paralysis, hypertension and heart disease. Vayu gets aggravated by the suppression of natural urges, eating food before the previous meal is digested, remaining awake for long at night, excessive shouting, too much physical exercise, excessive jerks when traveling in a vehicle for long time, intake of ingredients having pungent, bitter and astringent tastes, eating dry food, worry, sexual indulgence, fear, fasting, cold and grief. It also gets aggravated during the onset of the rainy season.

Pitta is a hot, sour and pungent liquid. It mainly governs the enzymes and hormones. Pitta is also responsible for digestion, pigmentation, body temperature, hunger, thirst, sight, courage and so forth. There are forty kinds of possible disturbances caused by pitta imbalance such as burning sensation and excessive temperature, blue moles, jaundice, urticaria and pharyngitis. Pitta gets aggravated by excessive intake of pungent and sour things, alcoholic beverages, saline, hot and sharp substances. Other responsible factors are anger, excessive exposure to sun, fire, fear, fatigue, intake of dry vegetables and alkalies. Indigestion and irregular eating habits also aggravate pitta. During autumn, pitta tends to get aggravated.

Kapha is unctuous, smooth, soft, sweet, firm, dense, cold, viscous and clear. Kapha is responsible for the connection and movement of the joints, the solid nature of the body and its sustenance, sexual power, strength, patience and so on. Among the twenty possible disturbances that can be caused by kapha imbalance are anorexia nervosa, laziness, mucous expectoration, hardening of blood vessels, obesity, suppression of digestive power and so forth. Thus the three doshas govern the physico-chemical and physiological activities of the body. Kapha becomes aggravated by sleeping during the day, overeating, by the intake of sweet, cold, heavy and sour things, fish, meat, preparation of sesame, sugarcane and milk, by intake of food and drinks containing excess salt and water and during the spring season.

Doshas are aggravated under certain conditions and diminished under some. Both states lead to disease. They can also be in a state of equilibrium, which is a condition of perfect health and is called sama.

The three doshas pervade all over the body. There are however some elements of the body in which they are primarily located. For example, the heart, the throat, the urinary bladder, the intestines, the pelvic region, the thighs, the two legs and the bones are the primary seats of vayu. The seats of pitta are the eyes, the skin, the lymph, the blood and the stomach. Similarly, the seats of kapha are the thorax, the head, the neck, the joints, the upper portion of the stomach and the fat tissues of the body.

During different seasons of the year, these doshas undergo certain changes. In India, for example, vayu gets aggravated between June and August, i.e. at the end of the summer. Pitta gets aggravated between October and December, i.e. during autumn, and kapha gets aggravated between February and April, i.e. during spring. In other countries, while the months of the season may vary, the doshas are aggravated by seasonal changes. If certain precautionary measures are not taken during these seasons, a person becomes prone to diseases caused by these doshas. These measures include undertaking therapies such as vomiting, purgation and enema before the onset of certain seasons, following specific regimens during them and taking different herbal preparations to counter the disease caused by aggravation of the doshas. For example, the herb, baritaki (Terminalia Chebula), may be taken in summer with jaggery, during the rains with rock salt, in autumn with sugar, in early winter with ginger powder of long pepper (Piper longum) and in spring with honey.

Each tissue which is also linked to one or more waste products which are known as malas, such as stool, perspiration, ear wax, fatty secretion of the skin, mucous, saliva, discharge from the eyes, and so on. An excess or deficiency in the production of the waste products is indicative of improper or inefficient functioning of the tissue elements and would therefore provoke a disease. The doshas will also then be in a disturbed state with one or more of them aggravated. The regular elimination of waste from the body is essential for maintaining good health.