What makes it leave and how can one recover from its loss?

In time, most people recover from the loss of loved ones.

It took Charlie several years to recover from the loss of his good friend.

The region recovered only slowly from the loss of people and buildings.

"I don't think it's possible to recover from the loss of a sister."

Day 140: I am recovering from my wounds and the loss of blood.

Presumably the were giving him some time and distance to help recover from his loss.

I'm not sure my father's ever recovered from the loss, but after that we had to do something to pass the time.

Bowie had never recovered from the loss of his loved ones.

Dave has recently lost his wife to cancer and is in need of a companion to help him recover from the loss.