According to the Alzheimer’s Association, more than 6 million Americans of all ages are living with Alzheimer’s; 1 in 3 seniors die having been diagnosed with some form of dementia or Alzheimer’s. The most common cause of dementia is Alzheimer’s disease, which accounts for up to 80 percent of dementia cases and is neurodegenerative, getting slowly and irreversibly worse over time. If saying a person has dementia is like saying a person is ill, then Alzheimer’s would be a specific cause of the illness. It may not seem like an important distinction, but treatments for one type of dementia and Alzheimer’s can vary. To sum up: A person with Alzheimer’s has dementia, but not everyone with dementia has Alzheimer’s.