ELI5: What is the difference between dementia and Alzheimer's?

The main difference is that dementia is an umbrella term for a general decline in memory and thinking that disrupts daily life, while Alzheimer's is a specific disease that causes that decline.

Think of it like being sick with a sore throat:

• Dementia is like having a "sore throat." It describes what you are experiencing—your throat hurts and it is hard to swallow. However, a sore throat is not the disease itself; it is just the trouble you feel.
• Alzheimer's is like "strep throat." It is the exact, specific germ that made your throat hurt in the first place.

Here is how it looks in everyday life:

• Normal everyday mistakes: We all lose our car keys sometimes, or forget why we walked into the kitchen, and then we laugh and remember later.
• Everyday life with dementia: A person might find their keys in the refrigerator, or forget what keys are used for, and they might have trouble following a recipe they have made for forty years.
• The Alzheimer's connection: If a doctor says this person has Alzheimer's, they have identified the exact reason for the trouble. In Alzheimer's, sticky proteins slowly build up in the brain like tangled spiderwebs, making it harder and harder for the brain's message-carriers to talk to each other.