Traditional Buddhism defines ‘dukkha’ in a number of different ways. 1. In the Four Noble Truths, dukkha is represented as ‘birth, old age, sickness and death; grief, sorrow, physical and mental pain, and despair; involvement with what one dislikes and separation from what one likes; not getting what one wants; in summary, the five groups of grasping (pañcʾupādānakkhandhā, cf. SKHANDHA) are a source of suffering’. 2. Threefold dukkha is ordinary mental and physical pain (dukkha-dukkhatā), that is, pure or intrinsic suffering; suffering as the result of change (viparināma-dukkhatā), owing to the impermanent and ephemeral nature of things; and suffering due to the formations (san̄khāra-dukkhatā; sankhara), that is, the sense of saṃsāra or our own temporality and finiteness. 3. It is maintained that all sentient beings—whether gods, humans, pretas, animals, or inhabitants of hell—are subject to dukkha. Gods suffer the least in the hierarchy of different beings, and the inhabitants of hell the most.
It is by comparison with nirvāna that everything is apprehended as suffering. Therefore, the ‘truth’ of suffering is something which has to be discerned or discovered, like the truth of anicca. Hence it figures as a subject of contemplation (dukkhānupassanā, cf. VIPASSANĀ) in Buddhist meditational practice.
"Dukkha." The Concise Oxford Dictionary of World Religions. . Encyclopedia.com. (September 19, 2018). http://www.encyclopedia.com/religion/dictionaries-thesauruses-pictures-and-press-releases/dukkha
"Dukkha." The Concise Oxford Dictionary of World Religions. . Retrieved September 19, 2018 from Encyclopedia.com: http://www.encyclopedia.com/religion/dictionaries-thesauruses-pictures-and-press-releases/dukkha