There are a lot of things that medicine cannot cure, although you wouldn't know that if your only exposure to medicine was Dr. House. Problems which arise in medicine which cannot be accounted for with typical (or even atypical treatments). Take the following situation, for instance.
I had the pleasure of taking care of an elderly woman who presented with a pulmonary embolus. Easy fix, usually. The problem was, every time we put her on anticoagulation, she began bleeding from her colon. Colonoscopy and bleeding scan showed nothing, bleeding stopped once you stopped the anticoagulation. Usual solution would be to put in a device called an IVC filter, which we did. She left the hospital, but returned shortly after with more clots in her lungs. No source was identified for the clots. We again tried anticoagulation, bled profusely once again. We opted for aspirin and another anti-platelet agent, which she seemed to tolerate. Left the hospital, came in again, this time with more clots and a stroke, for good measure. The woman was clearly exasperated. I told her I did not have an answer for her problems, and neither did our hematologist, our GI guy, our neurologist or any of the several hospitalists she had seen. The problem was unfixable and I let her know this.
Patient: "So, what am I supposed to do? Just die?"
Me: "Ultimately, yes."
Patient: *sits up straight, cocks her head as if listening to something* "Really?"
Patient: "That's...actually comforting. Thank you, doctor."
I think there is some measure of comfort to be gained in realizing that you don't have to focus on anything other than just living. I suppose you could focus on the plans for your funeral and making arrangements for your estate, but I think that's a rather sad way to approach your mortality. The remainder of the visit the woman smiled and laughed and finally ended up choosing to go to rehab for the effects of the stroke, but only so she didn't have to be in a nursing home for awhile. I haven't seen her back since. The last I saw of her she looked...relieved. I hope it was genuine.