"Now this, monks, is the Noble Truth of dukkha: Birth is dukkha, aging is dukkha, death is dukkha; sorrow, lamentation, pain, grief, & despair are dukkha; association with the unbeloved is dukkha; separation from the loved is dukkha; not getting what is wanted is dukkha. In short, the five aggregates for clinging/sustenance are dukkha."-- SN LVI.11
"And what is the noble truth of dukkha? 'The six internal sense media,' should be the reply. Which six? The medium of the eye...the ear...the nose...the tongue...the body...the intellect. This is called the noble truth of dukkha."-- SN LVI.14
"The All is aflame. What All is aflame? The eye is aflame. Forms are aflame. Consciousness at the eye is aflame. Contact at the eye is aflame. And whatever there is that arises in dependence on contact at the eye -- experienced as pleasure, pain or neither-pleasure-nor-pain -- that too is aflame. Aflame with what? Aflame with the fire of passion, the fire of aversion, the fire of delusion. Aflame, I tell you, with birth, aging & death, with sorrows, lamentations, pains, distresses, & despairs."The ear is aflame. Sounds are aflame...
"The nose is aflame. Aromas are aflame...
"The tongue is aflame. Flavors are aflame...
"The body is aflame. Tactile sensations are aflame...
"The intellect is aflame. Ideas are aflame. Consciousness at the intellect is aflame. Contact at the intellect is aflame. And whatever there is that arises in dependence on contact at the intellect -- experienced as pleasure, pain or neither-pleasure-nor-pain -- that too is aflame. Aflame with what? Aflame with the fire of passion, the fire of aversion, the fire of delusion. Aflame, I say, with birth, aging & death, with sorrows, lamentations, pains, distresses, & despairs."
-- SN XXXV.28
"'Dukkha should be known. The cause by which dukkha comes into play should be known. The diversity in dukkha should be known. The result of dukkha should be known. The cessation of dukkha should be known. The path of practice for the cessation of dukkha should be known.' Thus it has been said. In reference to what was it said?"Birth is dukkha, aging is dukkha, death is dukkha; sorrow, lamentation, pain, distress, & despair are dukkha; association with what is not loved is dukkha, separation from what is loved is dukkha, not getting what is wanted is dukkha. In short, the five aggregates for sustenance are dukkha.
"And what is the cause by which dukkha comes into play? Craving is the cause by which dukkha comes into play.
"And what is the diversity in dukkha? There is major dukkha & minor, slowly fading & quickly fading. This is called the diversity in dukkha.
"And what is the result of dukkha? There are some cases in which a person overcome with pain, his mind exhausted, grieves, mourns, laments, beats his breast, & becomes bewildered. Or one overcome with pain, his mind exhausted, comes to search outside, 'Who knows a way or two to stop this pain?' I tell you, monks, that dukkha results either in bewilderment or in search. This is called the result of dukkha.
"And what is the cessation of dukkha? From the cessation of craving is the cessation of dukkha; and just this noble eightfold path -- right view, right resolve, right speech, right action, right livelihood, right effort, right mindfulness, right concentration -- is the path of practice leading to the cessation of dukkha.
"Now when a disciple of the noble ones discerns dukkha in this way, the cause by which dukkha comes into play in this way, the diversity of dukkha in this way, the result of dukkha in this way, the cessation of dukkha in this way, & the path of practice leading to the cessation of dukkha in this way, then he discerns this penetrative holy life as the cessation of dukkha."
-- AN VI.63