Facts on dementia and cognitive decline

WASHINGTON (Reuters) - A report from the U.S. Alzheimer's Association shows that 5.2 million Americans have Alzheimer's disease, the most common form of dementia.

Here are some facts about Alzheimer's and dementia:

Dementia is marked by a loss of memory and at least one of the following cognitive abilities:

-- The ability speak coherently and understand spoken or written language

-- The ability to recognize or identify objects

-- The ability to execute motor activities

-- The ability to think abstractly, make sound judgments and plan and carry out complex tasks

This decline must be severe enough to interfere with daily life

Mild cognitive impairment causes problems with memory, language or another essential cognitive function that are severe enough to be noticeable to others and show up on tests, but not severe enough to interfere with daily life.

Some people with mild cognitive impairment go on to develop dementia but the condition can also resolve.

(Reporting by Maggie Fox; Editing by Cynthia Osterman)