Ayurveda is a complete way of life.It is prevention-oriented, is free from harmful side-effects and treats the root cause of a disease rather than just the symptoms.
Ayurveda views illness as caused by an imbalance in a person's physical or mental constitution and therefore seeks to gently bring a person's body and mind back into a healthy balance.
Every Person (and thing) contain all three doshas. However, the proportion varies according to the individual and usually one or two doshas predominate.
Within each person the doshas are continually interacting with one another and with doshas in all of nature.
This explains why people can have much in common but also has an endless variety of individual differences in the way they behave and respond to their environment.
(References: Internet and Ayurvedic books)