How do I know if my mom has Alzheimer's?

A doctor diagnoses Alzheimer's disease by process of elimination -- making sure there is no other possible cause for the worrisome symptoms. Many different things can cause memory loss, for example. He also will run some simple cognition tests that have a high accuracy in diagnosing dementia. See this article, " The Path to an Alzheimer's Disease Diagnosis." It's important to have your mother see a doctor and get a professional opinion, for two reasons. 1) If another problem is causing symptoms, you want to have it properly treated, and 2) If it is Alzheimer's, knowing this for sure can better help both of you marshal resources and prepare for the future.