TANHA

Tanha (craving) and upadana (clinging) are considered the two primary causes of dukkha (suffering, anxiety, dissatisfaction) in Buddhism.

Tanha literally means "thirst," and is commonly translated as craving or desire.  This is the craving or desire to hold onto pleasurable experiences, to not have painful or unpleasant experiences, and to not have neutral experiences or feelings diminish. The Buddha identified three types of tanha:

Sense-craving is the craving for sense objects which provide pleasant feelings, and for sensory pleasures, generally.
Craving to be is the craving to unite with an experience for the purpose of becoming something.
Craving not to be is the craving to not experience the world for the purpose of being nothing.  More generally, it is the craving for destruction, and, otherwise, as the Dalai Lama states, "a wish to be separated from painful feelings."

The cessation of craving leads to Nirvana.