brain, spinal cord, and nerve disorders
Delirium
Introduction
Delirium is a sudden, fluctuating, and usually reversible disturbance of mental function. It is characterized by an inability to pay attention, disorientation, an inability to think clearly, and fluctuations in the level of alertness (consciousness). Many disorders, medications, recreational drugs, and poisons cause delirium. Doctors base the diagnosis on symptoms and results of a physical examination, and they use blood, urine, and imaging tests to identify the cause. Promptly correcting or treating the condition causing delirium usually cures it. (See also Overview of Delirium and Dementia .) Delirium is an abnormal mental state, not a disease. Although the term has a specific medical definition, it is often used to describe any type of confusion. Although delirium and Dementia both affect thinking, they are different. Delirium affects mainly attention, and dementia affects mainly memory. Delirium begins suddenly and often has a definite beginning point. Dementia typically begins gradually and has no definite beginning point (see table Comparing Delirium and Dementia ). Delirium is never normal and often indicates a usually serious, newly developed problem, especially in older people. People who have delirium need immediate medical attention. If the cause of delirium is identified and corrected quickly, delirium can usually be cured. Because delirium is a temporary condition, determining how many people have it is difficult. Delirium affects 15 to 50% of hospitalized people. Delirium may occur at any age but is more common among older people. Delirium is common among residents of nursing homes. When delirium occurs in younger people, it is usually due to drug use (prescription, over-the-counter, or recreational) or a life-threatening disorder. Confusion means different things to different people, but doctors use the term to describe people who cannot process information normally. Confused people cannot Follow a conversation Answer questions appropriately Understand where they are Make critical judgments that affect safety Remember important facts Confusion has many different causes, including the use of certain drugs (prescription, over-the-counter, and recreational) and a wide variety of disorders. Delirium and dementia, though very different disorders, both cause confusion. When a person is confused, doctors try to determine what the cause is, particularly whether it is delirium or dementia. If confusion develops or worsens suddenly, the cause may be delirium. In such cases, medical attention is needed immediately because delirium may be caused by a serious disorder. Also, treating the cause, once identified, can often reverse the delirium. If confusion develops slowly, the cause may be dementia. Medical attention is needed but not urgently. Treatment may slow the mental decline in people with dementia but usually cannot stop the decline. 