What Happens

Researchers have discovered changes that take place in the brains of people who have Alzheimer's disease. These brain changes may cause the memory loss and decline in other mental abilities that occur with Alzheimer's disease. It is not fully understood why these brain changes occur in some people but not in others.

Alzheimer's disease always gets worse over time, but the course of the disease varies from person to person. Some people may still be able to function relatively well until late in the course of the disease. Others may lose the ability to do everyday activities very early on.

• The disease tends to get worse gradually. It usually starts with mild memory loss and progresses to severe mental and functional problems and eventual death.
• Symptoms sometimes are described as occurring in early, middle, and late phases. It is difficult to predict how long each phase will last.
• The average amount of time a person lives after developing symptoms of Alzheimer's disease is 8 to 10 years.

Mild dementia

Usually, a person with mild dementia:

• Becomes confused about where he or she is and gets lost easily.
• Loses the ability to start tasks on his or her own without prompting.
• Avoids new and unfamiliar situations.
• Has delayed reactions and slowed learning ability.
• Begins speaking more slowly than in the past.
• Develops difficulty handling money and paying bills.
• Starts using poor judgment and making inappropriate decisions.
• May have mood swings and become depressed, irritable, or restless.

These symptoms often are more obvious when the person is in a new and unfamiliar place or situation.

Some people have memory loss called mild cognitive impairment. People with this condition are at risk for developing dementia. But not all people with mild cognitive impairment progress to dementia.

Moderate dementia

With moderate dementia, a person typically:

• Has problems recognizing close friends and family.
• Becomes restless and wanders, especially in late afternoon and at night. This is called sundowning.
• Has problems reading, writing, and dealing with numbers.
• Has problems organizing thoughts and thinking logically.
• Can't find the right words to say or makes up stories to fill in the blanks.
• Has trouble dressing.
• Gets upset easily and can be hostile or unwilling to cooperate.
• Has firmly held false beliefs (delusions), suspicion of others (paranoia), and agitation.
• Needs full-time supervision.
• Loses recognition of time.

Severe dementia

With severe dementia, a person usually:

• Can no longer remember how to bathe, eat, dress, or go to the bathroom independently. The person may become bedridden or confined to a wheelchair because he or she has forgotten how to move.
• Loses the ability to chew and swallow.
• Has trouble with balance or walking and may fall frequently.
• Becomes more confused in the evening (sundowning) and has trouble sleeping.
• Cannot communicate using words.
• Loses bowel or bladder control (incontinence).

A person with severe dementia becomes more vulnerable to other illnesses. Death often results from complications of being confined to bed, such as pneumonia.