Alzheimer’s disease (AD) is an irreversible, progressive brain disease that slowly destroys memory and critical thinking skills, and may eventually destroy the ability to carry out even simple tasks. In most people with Alzheimer’s, symptoms first appear after age 60. Estimates vary, but experts suggest that as many as 5.1 million Americans may have Alzheimer’s disease.
There are two types of AD – early onset and late onset. In early onset AD, symptoms first appear before age 60. Early onset AD is much less common than late onset. It does, however, tend to progress more rapidly. Early onset disease can run in families and several genes variations have been identified as diagnostic. Late onset AD, the most common form of the disease, develops in people age 60 and older. Late onset AD may run in some families, but the role of genes is less clear.
The cause of AD is not entirely known, but is thought to include both genetic and environmental factors. A diagnosis of AD is made by the presence of symptoms in patients with no other apparent cause of dementia.
Dementia symptoms include difficulty with many areas of mental function, including:
- Emotional behavior or personality
- Cognitive skills (such as calculation, abstract thinking, or judgment)
The early symptoms of AD can include:
- Language problems, such as trouble finding the name of familiar objects
- Misplacing items
- Getting lost on familiar routes
- Personality changes and loss of social skills
- Losing interest in things previously enjoyed, flat mood
- Difficulty performing tasks that take some thought, but used to come easily, such as balancing a checkbook, playing complex games (such as bridge) and learning new information or routines
As the AD becomes worse, symptoms are more obvious and can include:
- Forgetting details about current events
- Forgetting events in life history, losing awareness of identity
- Change in sleep patterns, often waking up at night
- Difficulty reading or writing
- Poor judgment and loss of ability to recognize danger
- Using the wrong word, mispronouncing words, speaking in confusing sentences
- Withdrawing from social contact
- Having hallucinations, arguments, striking out and/or violent behavior
- Having delusions, depression, agitation
- Difficulty doing basic tasks, such as preparing meals, choosing proper clothing, and driving
People with severe AD can no longer:
- Understand language
- Recognize family members
- Perform basic activities of daily living, such as eating, dressing, and bathing
Other symptoms that may occur with AD include incontinence and swallowing problems.
If AD develops quickly, it is more likely to worsen quickly. Patients with AD often die earlier than normal, although a patient may live anywhere from 3 – 20 years after diagnosis. The final phase of the disease may last from a few months to several years. As the disease progresses, the patient may become immobile and totally disabled. Death usually occurs from an infection or organ failure.