The three doshas are the central part of the Ayurvedic philosophy. It is believed that these doshas are the three vital energies that compose our body. Each of us has a unique individual constitution though it is influenced by our parent's doshas at the time of conception along with other factors. We are born with different levels of these three doshas that are considered right for us and it is known as prakruti state. Ayurveda considers the best defense against almost all diseases is maintenance of strong constitution that is maintenance of perfect balance of all these three doshas. If our doshas are disturbed, aggravated or imbalanced through bad habits, food, over work etc. we become susceptible to illnesses. Ayurveda focuses on prevention of development of diseases by helping in proper maintenance of the constitution of the individual which aims at restoring it to its own Prakruti state.
As we know, we all have unique constitutions which are determined by the balance of vital energies in the body called three doshas or tridosha. The Sanskrit names of all the three doshas are vata, pitta and kapha. Each and every one of us is governed by all the three doshas in varying proportions in the body, but many of us are also governed by one of possibly two dominant doshas.
Ayurveda says the best defense against all plausible illness is a good constitution. If our bodies are functioning well the diseases are unlikely. But if the constitution is weakened we become susceptible to illnesses. Ayurveda aims at preventing diseases by working on individual constitution.