GAN and Alzheimer disease: The orderly pattern and treatment of SD according to the progression of AD starts with Shen (Kidney) deficiency to kidney-reinforcing treatment in aging, Pi (spleen) qi deficiency and Gan (liver) yin deficiency to spleen qi and liver yin-reinforcing treatment in mild cognitive impairment (MCI), progresses to phlegm and phlegm-resolving treatment in early AD, blood stasis and fire to blood activation and fire-purging treatment in middle-stage AD, and finally to severe toxin in advanced AD.