Confusion

The prospect of becoming confused strikes fear in the hearts of many older people. Older people fear that confusion will cause them to lose their identity and independence. They also fear that once they become confused, they will always be confused. However, confusion is not inevitable, and if it occurs, it is not necessarily permanent. Confusion has many causes. If the cause can be eliminated or treated, the confusion may disappear or lessen. Understanding what confusion is and what can cause it can help reduce the risk of becoming confused.

As people age, many changes occur in the brain. These changes make older people more susceptible than younger people to conditions that can disturb mental function. When mental function is disturbed in older people, they usually become confused.

Confusion has different meanings. But generally, it means that people cannot process information correctly. They cannot

• Follow a conversation
• Answer questions appropriately
• Pay attention to and understand what is going on around them
• Keep track of information
• Remember

Two disorders are characterized by confusion: delirium and dementia. They are very different and have very different causes. However, delirium and dementia may occur together.

Delirium occurs suddenly, typically over a period of hours to days. It is usually caused by the recent development of a condition that affects the brain's ability to function. The most obvious symptom of delirium is the inability to pay attention. How well people with delirium are able to pay attention may change over time. They may appear sluggish one moment and alert the next. Often, confusion is worse at night. People with delirium may be calm and focused one moment, then agitated and distracted the next. They cannot think clearly and thus cannot speak coherently. If the disorder causing delirium is quickly identified and successfully treated, confusion may disappear or lessen. Then, most people can function as well as they did before delirium developed.

Dementia develops slowly. It is usually caused by a chronic brain disorder. When dementia first develops, it, unlike delirium, does not interfere with the ability to pay attention. At first, the most obvious symptom is loss of memory. However, all aspects of mental function slowly and steadily deteriorate. Usually, dementia cannot be cured. Eventually, mental function is severely and permanently impaired. The development of a disorder or use of a new drug is more likely to lead to delirium in people with dementia than in those without dementia.

Confusion is always serious. People who suddenly become confused or whose confusion suddenly worsens may have delirium. Consequently, they need medical attention immediately. People with sudden confusion are often hospitalized to be evaluated and treated. People who gradually become more and more confused may have dementia. They also need medical attention but not so urgently. Such people rarely need to be hospitalized, but they need to be evaluated. For them, confusion can be evaluated over a period of days or weeks during a series of visits to the doctor's office. However, people who have dementia that suddenly worsens need to be evaluated more quickly.

See the table Comparing Two Disorders of Confusion.

Diagnosis

The first thing doctors need to know about the confused person is whether the confusion occurred suddenly or developed gradually. This information helps doctors determine whether the cause of confusion is delirium or dementia. To be sure of the diagnosis, doctors ask the person a standard series of questions, called a mental status test. These questions help doctors identify which mental functions are not working normally and to what degree.

Doctors also talk with a family member or another person who knows the confused person. Such a person can describe how the confused person used to be—days, weeks, and months ago—and exactly what has changed. Doctors may ask to see documents that can indicate a change in mental function, such as a checkbook, recent letters, or notification of unpaid bills or missed appointments. For example, a checkbook shows whether the person's writing has changed over a period of time, as well as how well the person can record entries and do math. Letters can indicate whether a person's thinking is confused.

Doctors ask other questions to help them identify the cause of the confusion. They ask about the disorders the confused person has and the drugs (including nonprescription drugs) and dietary supplements the person has been taking. Doctors may also ask whether the person is taking an illicit drug or consuming a substantial amount of alcohol.

Doctors ask detailed questions about the person's emotional health. This information is helpful because depression may be causing or contributing to confusion.

Evaluation of confusion always includes a complete physical examination and may include blood and other laboratory tests.

See the table What Is Mental Status Testing?