Lhe four noble truths are an expression of the deep understanding of reality that the Buddha had at the time of his awakening. It was shortly after that he shared this vision at the Parc des Gazelles in Sarnath during a first teaching called “The setting in motion of the Wheel of Dharma”. These four noble truths form the core of the Buddha's teaching.
The first noble truth is a simple observation: that of suffering (dukkha). Indeed, if we honestly look at our existence, we cannot deny the suffering it contains: from its beginning, at birth, there is suffering for the mother as well as for the child. Other stages such as old age and death also involve a lot of suffering. Traditionally, the Buddha enumerates seven kinds of suffering. Besides birth, old age and death, it reminds us that illness is suffering, that not having what we want is suffering, that being separated from what we love is suffering, just like being associated what we don't like.
The Sanskrit term dukkha not only represents suffering in the physical sense but also all the dissatisfaction we feel as human beings. Also dukkha has a much broader meaning covering all forms of dissatisfaction and frustration related to imperfection, impermanence, disharmony, and insubstantiality. When we speak of the noble truth of dukkha, we are therefore talking about human suffering in all its aspects.