Suffering (Skt. duhkha) is the first of the four truths of the noble ones taught by the Buddha in his first teaching:

“What is suffering? It is the pain that accompanies birth, growing old, falling sick, and dying. It also includes the suffering of meeting the unpleasant and parting from the pleasant. Not finding what is being sought is also suffering. In short, the five perpetuating aggregates are suffering. This is what we call suffering.” (Lalitavistara Sutra)

In the quote above, eight types of suffering are identified; namely the sufferings of:

(1) birth,

(2) old age,

(3) sickness,

(4) death,

(5) meeting what is unpleasant,

(6) parting from what is pleasant,

(7) not finding what is being sought, and

(8) the five aggregates.

The noble eightfold path, which is part of the truth of the path, is taught as an antidote to these eight types of suffering.

These eight types of sufferings can also be condensed into three:

(1) suffering of suffering

(2) suffering of change

(3) all-pervasive suffering of conditioning

Source: https://www.rigpawiki.org/index.php?title=Suffering