The first fundamental theory of the Unani system was established by Greek philosopher Hippocrates. Unani system follows the humoural theory which postulates the presence of four humours in the body: dam (blood), balgham (phlegm), safra (yellow bile) and sauda (black bile), a parallel to kapha, vata and pitta, the three doshas in ayurveda.

As long as these humours exist in normal balance, normal quantities and in the normal region of the body, the humour system will work in the normal way. Any imbalances to the humour constitutions or changes in their quantity and quality results in diseases.

Unani medicine, like any other form of medical science strives to find the best possible ways by which a person can lead a healthy life. It prescribes drugs, diet, drinks and other regiments including codes of conduct which are conducive to the maintenance and promotion of positive health, as well as the prevention and cure of disease.

The ultimate aim of these scientific prescriptions and prohibitions is the creation of a healthy society.It emphasizes on retaining natural compounds which belong to the human body, and hence prescribes only natural remedies. Unani medicine believes that diseases can be kept at bay by the use of clean and fresh water, breathing clean air and consuming fresh food.

Likewise, a balance should be maintained between the mind and the body so that the metabolic process can take place easily and the body waste evacuated. Unani medicine also believes that all
life forms have originated from the sea.