This is the most popular one, probably because it was the first one described almost a hundred years ago by Dr. Alois Alzheimer. People with AD have progressive (meaning it gets worse over time) memory loss. The memory loss may first involve minor things, like forgetting something that was stated a few minutes ago. As the disease worsens, the person forgets how to do things (called “praxis”) in the reverse order in which he or she learned the task. Most of us learned tasks in the following order: swallow, feed ourselves with our fingers, crawl, walk, talk, use utensils to eat, go potty, dress ourselves, brush our teeth, tie our shoes, read, ride a bike, drive, use a computer (for the millennials, that task probably occurred after “crawl”), balance a checkbook, and so forth. With AD, the tasks are “lost” in the order in which they were learned. I have seen individuals who were fluent in several languages lose their ability to speak and understand those languages, starting with the language learned latest in life. AD can occur early, that is, in individuals under the age of 65 (early onset AD) or later in life (late-onset AD in persons 65 years of age or older). Early onset AD is usually hereditary and the genes can be identified. I Late-onset AD is probably due to a mix of genetic risk and lifestyle choices. For more information, please visit the Alzheimer’s Association’s web site and Alzheimer’s of Central Alabama website.