In a person who is physically healthy, the three doshas are present in appropriate proportions, their quality is pure, and their activities are calm and orderly. That person has strong, stable energy, good digestion, flexible joints, clear thinking, calm demeanor, glowing complexion, and is able to sleep well. In a person who is unhealthy, at least one, but almost always two or all three of the doshas are relatively deficient or excessive, their quality has become impure, and their activities disorderly. These latter two aspects, impurity and disruption, are commonly called "vitiation" (the doshas are "vitiated"), meaning corrupted. A term for imbalance of the doshas is tundoskopa: anger of the doshas, capturing the idea that the doshas have an active role in the disease process, not just a passive one of being deficient or excessive in amount.
Following are some of the expected manifestations of deficiency, excess, and aggravation (vitiation) of the individual doshas:
Kapha deficiency: sensation of dryness or internal burning, feeling of emptiness in the stomach and other cavities of the body, looseness of the joints, thirst, weakness, and insomnia.
Kapha excess: whiteness of complexion, heaviness of limbs, nausea and fullness of the stomach, feeling of coldness, drowsiness, excessive sleep, and looseness of the joints.
Kapha vitiation: aversion to food, inertness of limbs, vomiting, and impaired digestion.
Pitta deficiency: dullness of complexion and reduced body heat.
Pitta excess: burning sensation of the body, desire for coolness, yellowish coloration (of skin, eyes, feces, urine), insufficient sleep, fainting fits, weakness of sense organs.
Pitta vitiation: heat (fever or hot sensation).
Vata deficiency: languor, uneasiness, loss of consciousness.
Vata excess: roughness of the voice, thinness of the body, dark complexion, desire for heat, throbbing sensation, hard stool, insomnia, and weakness.
Vata vitiation: swelling or distention of the abdomen, rumbling sound of the intestines.
Each of the doshas has a location in the body where it generates the corresponding humors and from which it initiates its actions. These sites are also where vitiation of the doshas and humors is most likely to occur. Kapha has its seat in the stomach, pitta in the small intestine, and vata in the large intestine. That is, the three doshas have their initial and dominant influence in the gastro-intestinal system.
The principal site of action for each of these influences explains the importance attributed to food consumption by Ayurvedic doctors. Food enters the gastro-intestinal system and portions of it encounter, one by one, the seats of the three doshas. Interacting with the doshas, the food is transformed and transported and made into the substance of the body and activates the movement of the body. Persons who are sluggish and those who are agitated may each suffer from a disorder in the transformation of food into usable energy and substance; an important aspect of this is the production of unhealthy byproducts, known as ama.
Dietary adjustments, along with the use of herbs, are the most important aspects of healing regimens, at least for long-term therapy. Dietary factors are not the only ones that affect the body, so herbs, massage, and other techniques are also important. Yet, one should not forget the underlying basis of Ayurveda, which is not physical medicine, but spiritual medicine: it is the unsettled spirit and the mind not open to full consciousness that remains at the root of these problems.