Alzheimer's disease (AD) is a progressive neurodegenerative disease with occult onset. Its clinical manifestations include memory disorder, aphasia, apraxia, agnosia, visuospatial skill disorder, executive dysfunction and personality and behavior changes.

Alzheimer's disease is devastating: it usually takes only seven years from diagnosis to death. So far, no medicine or treatment can slow down the progress of the disease, let alone cure it.

At present, many critical illness insurances have covered this disease.