What Is Dementia?

Dementia is the loss of cognitive functioning — thinking, remembering, and reasoning — to such an extent that it interferes with a person's daily life and activities. Some people with dementia cannot control their emotions, and their personalities may change. Dementia ranges in severity from the mildest stage, when it is just beginning to affect a person's functioning, to the most severe stage, when the person must depend completely on others for basic activities of living.

Dementia is more common as people grow older (about one-third of all people age 85 or older may have some form of dementia) but it is not a normal part of aging. Many people live into their 90s and beyond without any signs of dementia.

There are several different forms of dementia, including Alzheimer’s disease. A person’s symptoms can vary depending on the type.

What are the symptoms of Dementia?

Signs and symptoms of dementia result when once-healthy neurons, or nerve cells, in the brain stop working, lose connections with other brain cells, and die. While everyone loses some neurons as they age, people with dementia experience far greater loss.

The symptoms of dementia can vary and may include:

• Experiencing memory loss, poor judgment, and confusion
• Difficulty speaking, understanding and expressing thoughts, or reading and writing
• Wandering and getting lost in a familiar neighborhood
• Trouble handling money responsibly and paying bills
• Repeating questions
• Using unusual words to refer to familiar objects
• Taking longer to complete normal daily tasks
• Losing interest in normal daily activities or events
• Hallucinating or experiencing delusions or paranoia
• Acting impulsively
• Not caring about other people’s feelings
• Losing balance and problems with movement

People with intellectual and developmental disabilities can also develop dementia as they age, and recognizing their symptoms can be particularly difficult. It’s important to consider a person’s current abilities and to monitor for changes over time that could signal dementia.

What causes dementia?

The causes of Alzheimer’s and related dementias can vary, depending on the types of brain changes that may be taking place. While research has found that some changes in the brain are linked to certain forms of dementia, in most cases, the underlying causes are unknown. Rare genetic mutations may cause dementia in a relatively small number of people.

Although there is no proven prevention, in general, leading a healthy lifestyle may help reduce risk factors that have been associated with these diseases.

How is dementia diagnosed?

To diagnose dementia, doctors first assess whether a person has an underlying, potentially treatable, condition that may relate to cognitive difficulties. A physical exam to measure blood pressure and other vital signs, as well as laboratory tests of blood and other fluids to check levels of various chemicals, hormones, and vitamins, can help uncover or rule out possible causes of symptoms.

A review of a person’s medical and family history can provide important clues about risk for dementia. Typical questions might include asking about whether dementia runs in the family, how and when symptoms began, changes in behavior and personality, and if the person is taking certain medications that might cause or worsen symptoms.

The following procedures also may be used to diagnose dementia:

• Cognitive and neurological tests. These tests are used to assess thinking and physical functioning. These include assessments of memory, problem-solving, language skills, and math skills, as well as balance, sensory response, and reflexes.
• Brain scans. These tests can identify strokes, tumors, and other problems that can cause dementia. Scans also identify changes in the brain's structure and function. The most common scans are:
  • Computed tomography (CT), which uses X-rays to produce images of the brain and other organs
  • Magnetic resonance imaging (MRI), which uses magnetic fields and radio waves to produce detailed images of body structures, including tissues, organs, bones, and nerves
  • Positron emission tomography (PET), which uses radiation to provide pictures of brain activity
• Psychiatric evaluation.This evaluation will help determine if depression or another mental health condition is causing or contributing to a person's symptoms.
• Genetic tests. Some dementias are caused by a person’s genes. In these cases, a genetic test can help people know if they are at risk for dementia. It is important to talk with a genetic counselor before and after getting tested, along with family members and the doctor.
• Blood tests. It is now possible for doctors to order a blood test to measure levels of beta-amyloid, a protein that accumulates abnormally in people with Alzheimer’s. Several other blood tests are in development. However, the availability of these diagnostic tests for Alzheimer’s and related dementias is still limited.

arly detection of symptoms is important, as some causes can be treated. However, in many cases, the cause of dementia is unknown and cannot be treated. Still, obtaining an early diagnosis can help with managing the condition and planning ahead.