Is Dementia the beginning of Alzheimer's?

Dementia is a general term for any loss of the mental status and function.
Alzheimer's is a very specific kind of dementia, which is diagnosed by detailed testing and brain imaging.
Vascular dementia is the kind caused by strokes or mini-strokes.
Lewy Body dementia is another type. There are MANY different things that cause dementia, including alcohol, long term medication use, brain injury, infection and chemicals. See the MD ASAP.

What about when they mimmick your body language, and use the same words you did, from previous conversations? Even though everything I say and do is wrong.
It starts out dementia and grows in to alzheimer's?

ladaustell, is your uncle under a doctor's care? What does the doctor say is wrong? There could be a few things that could cause these symptoms. Some of them are treatable, others are not so easy to treat. Maybe you can start a new thread so that people will provide answers to your question alone.

my uncle is wetting himself and can't remember to take a bath and losing weight real bad he has black out plenty of time and also can't remember thing and has a real cough

Have to add that dementia is a symptom of other diseases, too. Any disease of the brain that alters cognition can cause dementia. Examples are vascular dementia or the various Lewey body dementias.

Dementia is a symptom of Alzheimer's. One of the regions most affected by the disease is the hippocampus. This is a part of the brain that is involved in processing short-term memory. As the hippocampus becomes progressively more damaged, it becomes harder to remember things that are happening at the present or recent times. A persistent short-term memory problem is usually the first symptom noticed for Alzheimer's.

I'm wanting to know if Alzheimers is Dementia?