Dukkha (Pāli; Sanskrit: duḥkha; Tibetan phonetic: dukngal) is a Buddhist term commonly translated as "suffering", "stress", "anxiety", or "dissatisfaction". Dukkha is identified as the first of the Four Noble Truths.

Within the Buddhist tradition, dukkha is commonly explained according to three different patterns or categories. In the first category, dukkha includes the obvious physical suffering or pain associated with giving birth, growing old, physical illness and the process of dying. These outer discomforts are referred to as the dukkha of ordinary suffering (dukkha-dukkha). In a second category, dukkha also includes the anxiety or stress of trying to hold onto things that are constantly changing; these inner anxieties are called the dukkha produced by change (vipariṇāma-dukkha). The third pattern or category of dukkha refers to a basic unsatisfactoriness pervading all forms of life, due to the fact that all forms of life are impermanent and constantly changing. On this level, the term indicates a lack of satisfaction, a sense that things never measure up to our expectations or standards. This subtle dissatisfaction is referred to as the dukkha of conditioned states (saṃkhāra-dukkha).