The first of the Four Noble Truths is the Truth of Suffering.
What is suffering? Buddhism describes three levels or types of suffering. This is called ‘the suffering of suffering’, the second, ‘the suffering of change’, and the third is ‘the suffering of conditioning’.
The suffering of suffering: the suffering of birth, sickness, aging, and death.
The suffering of change: things we would normally think as pleasurable.
The suffering of conditioning: What is the nature of things? Eveything happens in samsara is due to ignorance
(complied from ‘The Four Noble Truths’ by H.H. The 14th Dalai Lama, fourteenth printing – 2009)