Alzheimer's Disease Overview
Alzheimer's disease (AD) is the most common cause of
dementia in industrialized nations. Dementia is a brain disorder that interferes with a person's ability to carry out everyday activities.
- The brain of a person with Alzheimer's disease (see
Multimedia file 1) has abnormal areas containing clumps (senile plaques) and
bundles (neurofibrillary tangles) of abnormal proteins. These clumps and
tangles destroy connections between brain cells.
- This usually affects the parts of the brain that
control cognitive (intellectual) functions such as thought, memory, and
- Levels of certain chemicals that carry messages
around the brain (neurotransmitters) are low.
- The resulting losses in intellectual ability are called dementia when they are severe enough to interfere with everyday functioning.
Alzheimer's disease affects mainly people aged 60 years or older.
- The risk of developing Alzheimer's disease
continues to increase with age. People aged 80 years, for example, have a
significantly greater risk than people aged 65 years.
- About 5 million people in the United States and more
than 30 million people worldwide have Alzheimer's disease. Many others have
mild, or minimal, cognitive impairment, which frequently precedes dementia.
- The number of people with Alzheimer's disease is
expected to rise substantially in the next few decades because of the aging of
- The disease affects all races and ethnic groups.
- It seems to affect more women than men.
Alzheimer's disease is a progressive disease, which means that it gets worse over time. It cannot be cured or reversed by any known treatment.
- The symptoms often are subtle at first.
- Over time, people with the disease lose their ability
to think and reason clearly, judge situations, solve problems, concentrate,
remember useful information, take care of themselves, and even speak.
- Changes in behavior and personality are common.
- People with mild Alzheimer's disease usually require
close supervision and help with everyday tasks such as cooking, shopping, and
- People with severe Alzheimer's disease can do little on their own and require complete full-time care.
Because of this, Alzheimer's disease is considered a major public health problem.
- The cost of caring for people with the disease is
estimated at over $100 billion per year in the United States. The average
yearly cost per affected person is $20,000 to $40,000, depending on the
severity of the disease.
- That cost doesn't take into account the loss of quality of life for the affected person, nor the physical and emotional toll on family caregivers.
Nestor Galvez-Jimenez, MD
Francisco Talavera, PharmD, PhD
Patient Comments & Reviews
The eMedicineHealth doctors ask about Alzheimer's Disease: