system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do people with cancer seem to get one last burst of energy in the week or so before they die?

I have had four people that I have known die of cancer.  One died within weeks of being diagnosed with stomach cancer.  The other three however went through the torturous multi-year process of fighting the disease.  In each case, there were times when the person looked literally near death - frail, tired, unresponsive.  Just not themselves.  Then in each case a few weeks before they finally died they suddenly perked up.  Not a little.  A lot.  They got color, energy, and seem excited about the future.  If you didn't know it you would bet these were healthy happy people planning to live a long prosperous life.  And then, the downfall comes fast and furious and in a matter of days they are gone.

Why does this happen medically?
gpt
Probably because the treatments can physically take you down harder than the disease itself. Yes the cancer is fatal, but without chemo and a host of other drugs, your body kinda recovers and feels significantly better than the treatments leading up to that point.