Flu Is it a Cold, the Flu, or COVID-19? Learn about common symptoms of a cold, flu, and COVID-19 in this NIA infographic. Download, print and share it with your friends and family. Alzheimer's Disease: Common Medical Problems When caring for someone with Alzheimer's disease, watch for these common medical problems, including fever, pneumonia, dehydration, incontinence, and falls. Flu and Older Adults Learn all about flu—how it spreads, symptoms and treatment, the difference between cold, flu, and COVID-19, and the importance of getting a flu shot.