In relation to pain, you just learn to deal with it, as simple as that. There is no formula for it, you just learn from what happens, assume that situation and carry it as best you can, give the best as a person and human being. If the situation is something very close to you, you can give "light" to that person while he/she lives, giving him/her pleasant moments while understanding that "that is the best we can do". I had a cousin who died of cancer at the age of 12, very unfortunate because she died in the "flower" of life.
Commented by @hojaraskita