Dementia is not a single disease; it’s an overall term — like heart disease — that covers a wide range of specific medical conditions, including Disorders grouped under the general term “dementia” are caused by abnormal brain changes.

These changes trigger a decline in thinking skills, also known as cognitive abilities, severe enough to impair daily life and independent function. They also affect behavior, feelings and relationships.

Alzheimer’s disease accounts for 60 to 80 percent of cases. which occurs because of microscopic bleeding and blood vessel blockage in the brain, is the second most common cause of dementia. But there are many other conditions that can cause symptoms of dementia, including some that are reversible, such as thyroid problems and vitamin deficiencies.

Dementia is often incorrectly referred to as “senility” or “senile dementia,” which reflects the formerly widespread but incorrect belief that serious mental decline is a normal part of aging.
loss and other symptoms of dementia
Symptoms of dementia can vary greatly. Examples include:

• problems with short-term memory
• keeping track of a purse or wallet
• paying bills