Suffering

I had finished last night shift, I had changed my clothes and I was walking out, when I crossed in a corridor a middle age lady on a bed, being pushed. Walking behind, a man, possibly a boyfriend or a husband. On her face there was a lot of suffering and grief.

And a question crossed my mind: what is the origin of all human suffering?.
Then I realized the Buddha had asked that question and answered it....but I did not remember his answer. Can we leave that question open, for as long as it takes, without taking answers from anybody?