The cause of suffering is attachment to desire. Suffering ends by letting go of attachments. Letting go happens by developing the Noble Eight-Fold Path. The Buddha said that all experiences from the most delightful to the most painful, are transient, unreliable and unsatisfactory. They come and go.
Nothing lasts and change is inevitable.
This in itself can be painful. The Buddha made a crucial distinction between the suffering you experience because of the inevitability of change and the suffering we create for ourselves because we want things to be different than they are. When you forget that everything changes, you set up a struggle that creates suffering. You want things to be different than they actually are. When there is a struggle, there's suffering.