Most typically, memory loss in older people is caused by:

a) Alzheimer's disease.
b) too many things to remember.
c) a variety of factors, including certain medications and chronic conditions.

Some memory loss is natural with age. For instance, forgetting where you just left your glasses is normal. However, forgetting that you wear glasses is not.

Memory loss in older people can have many causes and often can be treated. While Alzheimer's disease or other dementing disorders can cause memory loss, other factors can include depression, reactions to some drugs, and head injury.