Dementia

Dementia is not a specific disease. Instead, it is the name for a group of symptoms caused by disorders that affect the brain and are associated with a decline in memory or other thinking skills that is severe enough to reduce a person's ability to perform everyday activities. People with dementia may not be able to think well enough to do normal activities, such as getting dressed or eating. They may lose their ability to solve problems or control their emotions. Their personalities may change. They may become agitated or see things that are not there.

Memory loss is a common symptom of dementia. However, memory loss by itself does not mean you have dementia. People with dementia have serious problems with 2 or more brain functions, such as memory and language. Although dementia is common in very elderly people, it is not part of normal aging.

Many different diseases can cause dementia, including Alzheimer's disease and stroke. Alzheimer's disease accounts for 60 to 80 percent of cases of dementia. Vascular dementia, which occurs after a stroke, is the second most common type of dementia. Many other conditions can cause symptoms of dementia, including some that are reversible, such as thyroid problems and vitamin deficiencies.

No treatment can cure dementia. However, some drugs may help improve symptoms or slow the decline in mental abilities.

Dementia involves damage of nerve cells in the brain, which may occur in several areas of the brain. This damage interferes with the ability of brain cells to communicate with each other. When brain cells cannot communicate normally, thinking, behavior and feelings can be affected.

Dementia may affect people differently, depending on the area of the brain affected. The brain has many distinct regions, each of which is responsible for different functions (for example, memory, judgment and movement). When cells in a particular region are damaged, that region cannot carry out its functions normally.

Dementias can be classified in a variety of ways and are often grouped by what they have in common, such as what part of the brain is affected, or whether they worsen over time (progressive dementias). Some dementias, such as those caused by a reaction to medications or an infection, are reversible with treatment.

Most changes in the brain that cause dementia are permanent and worsen over time, but thinking and memory problems caused by the following conditions may improve when the condition is treated or addressed:

• Depression
• Medication side effects
• Excess use of alcohol
• Thyroid problems
• Vitamin deficiencies

Many factors can eventually lead to dementia. Some factors cannot be changed, but others can be addressed to reduce your risk of developing dementia:

• Age. The risks of several types of dementia increase after age 65. However, dementia is not a normal part of aging, and dementia can occur in younger people.
• Family history. A family history of dementia, increases the risk of developing dementia.
• Down syndrome. By middle age, many people with Down syndrome develop the plaques and tangles in the brain that are associated with Alzheimer's disease. Some may develop dementia.
• Heavy alcohol use. People who consume large amounts of alcohol may have a higher risk of dementia. Although studies have shown that moderate amounts of alcohol may have a protective effect, abuse of alcohol increases your risk of developing dementia.
• Atherosclerosis. This buildup of fats and other substances in and on the artery walls (plaques) can reduce the blood flow to the brain and lead to stroke. Reduced blood flow to your brain can also cause vascular dementia.
• Blood pressure. High or low blood pressure may increase the risk of developing dementia.
• Cholesterol. High levels of low-density lipoprotein (LDL) cholesterol may increase the risk of developing vascular dementia or Alzheimer's disease.
• Depression. Although not yet well understood, late-life depression, especially in men, may be related to the development of dementia.
• Diabetes. Diabetes may increase the risk of developing Alzheimer's disease and vascular dementia.
• High estrogen levels. Women taking estrogen and progesterone years after menopause may be at greater risk of developing dementia.
• Homocysteine blood levels. Elevated blood levels of homocysteine, a type of amino acid produced by the body, may increase the risk of developing vascular dementia.
• Obesity. Being overweight or obese may increase the risk of developing dementia.
• Smoking. Smoking may increase the risk of developing dementia and blood vessel (vascular) diseases.

Talk with a doctor about memory loss, confusion, or personality changes that interfere with daily life. An evaluation can identify treatable causes and guide care and planning.