system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: how is Alzheimer's disease fatal?
gpt
Alzheimer's disease is a progressive neurological degeneration. Basically it causes the progressive loss of neurons, which are the cells in your brain that make up your nervous system.

While the early symptoms of Alzheimer's disease are the common forgetfulness, loss of abstract thought, etc., as the disease becomes more severe you start to pretty much lose the ability to take care of yourself at all. Complete lack of speech, total apathy, exhaustion, etc. Patients tend to die "with" Alzheimer's more than they die "of" it - dying of a complication like pneumonia or an infection that they get from being bedridden.