AYURVEDA means science of life, it is one of the most ancient natural medicine systems in the world. Each person is unique and Ayurveda treats the patient in contrast to conventional medicine that treats the sickness. Ayurveda uses the knowledge of the PRAKRUTI, the patient’s constitution.
There are three DOSHAS known as VATA, PITTA and KAPHA and these doshas harmonize the functions of each cell and are present in each cell. When the spermatozoids and the ovule are uniting inside your mother’s uterus, a zigote is created, the doshas which are present inside and outside at that time are producing the PRAKRUTI; if the doshas are in harmony, the baby will be in good health, if not, the fetus will not survive or will be not well formed. 
When one or two of the doshas are in excess, they will create a particular constitution on the physical and psychological plan that will characterize a person and will never change.
There are 7 types of prakruti:
VATA
PITTA
KAPHA
VATA-PITTA
PITTA-KAPHA
VATA-KAPHA
SAMA
Knowing the prakruti is very important in ayurvedic diagnosis, because for example, a vata (air) person will tend to have vata disorders, the other type of sicknesses are rare for him or easy to dislodge. In order to prevent vata sicknesses, one should avoid food, drink and factors aggravating vata. In the same way a pitta (fire) person should be given remedies that are refreshing and a kapha (cold) type medicines that are heating. The prakruti are SATWIKA, RAJA and TAMAS. The concept of the spirit is very important because ayurveda considers that a sickness is physical and mental. Mental has a dominant role in the cause of the disease.

Psychological factors have a control on the physiological functions in the body and also the contrary. Then the physical body is treated with psychic treatments.