There are 3 main diseases of mind which gives pain.
It is a subtle form of desire; it's hidden desire. Vasanas assume the form of desire which is gross. Vasanas produce Samskaras (impressions) and Samskaras in turn generate Vasanas. The rotation of this never-ending wheel of Vasana and Samskara constitutes the Samsara Chakra which causes births and deaths. There are two kinds of vasanas - the pure and the impure. Pure vasanas liberate one from rebirth. Impure vasanas cause the mind to fluctuate, producing agitation in the mind and affinity for objects. The impure vasanas are categorized into following 3 vasanas:
- Lok-Vasana (World related): It prompts one to achieve name and fame, seek power over others and aspire for honours and distinctions. As a result, one develops a narrow egoistic outlook and fails to realise the impermanence and transient nature of all worldly pleasures and possessions. 'I want to be always praised by everyone'. This is called impure because it is something impossible of achievement.
- Deha-Vasana (Body related): It impels one to seek physical strength and health and an attractive physique. All the efforts to make up one's face will not serve to alter the natural features of persons. Only that which has been given by the Lord will be enduring. You must be content with that. While taking as much care of the body as is essential, you should not have excessive attachment to that which is inherently perishable and temporary. The body must be taken care of only for realising the Divinity within. It is no doubt necessary to maintain good health as long as one lives, but obsessive concern for the body is misconceived.
- Sastra-Vasana (Scripture related): Addiction to many scriptural texts is also an impure vasana because it is not the highest aim.
From Vasana flows the stream of desire and from enjoyment of objects of desires arises Trishna or internal craving (intense longing). Trishna is very powerful.
Mind gets anxiety when the desires are not fulfilled.