Vietnamese Thiền understands suffering, *khổ*, as a pervasive quality of conditioned existence rather than only as obvious pain or misfortune. It includes physical and emotional distress, the instability of pleasant experiences, and the subtle sense of dissatisfaction that runs through ordinary life. Birth, aging, sickness, death, separation from what is loved, and contact with what is disliked are all seen as expressions of this fundamental unsatisfactoriness. This perspective highlights that much of what is experienced as suffering arises not simply from external conditions, but from the way the mind relates to those conditions.

The causes of suffering are traced to attachment and ignorance, articulated through the classical framework of the Three Poisons: greed (*tham*), hatred or aversion (*sân*), and delusion (*si*). Craving and clinging to impermanent things—possessions, relationships, roles, ideas, and even spiritual attainments—create inevitable frustration when change occurs. At the root of this clinging lies ignorance (*vô minh*): not understanding impermanence, interdependence, and the absence of a permanent, separate self. This ignorance leads to ego-attachment, the construction of a solid “I” opposed to “others,” which in turn fuels desire, fear, and conflict.

Thiền also emphasizes that the deepest cause of suffering is a failure to recognize one’s true Buddha-nature. Because this innate clarity and capacity for awakening are overlooked, experience is filtered through grasping and resistance, and reality is misperceived. Suffering is thus seen as a distortion of what is already present and whole, rather than as something imposed from outside. Realization of Buddha-nature is not treated as an abstract doctrine but as a living possibility, to be directly realized through meditation, mindfulness, and ethical conduct.

Within this vision, the path of practice is a process of seeing through ignorance and loosening the knots of attachment. By contemplating impermanence and interdependence, and by observing the Three Poisons as they arise in body, speech, and mind, practitioners gradually transform the conditions that give rise to suffering. As understanding deepens, compassion naturally expands, and the habitual patterns that perpetuate dissatisfaction begin to fall away. Liberation is described not as escape from the world, but as a clear, unobstructed way of being within it, in which suffering and its causes are understood and no longer bind the heart.