Dementia is a progressive loss of mental function due to certain diseases that affect the brain. The losses are substantial. Over time, all types of dementia will lead to loss of memory, loss of reasoning and judgment, personality and behavioral changes, physical decline, and death.

Dementia isn’t a disease. Instead, it’s a group of symptoms caused by other conditions. You might also hear it called major neurocognitive disorder.

About 5%-8% of adults over age 65 have some form of dementia. This percentage doubles every 5 years after 65. As many as half of people in their 80s have some dementia.

Alzheimer’s disease is the most common cause of dementia. Between 60%-80% of people with dementia have Alzheimer’s. But there are as many as 50 other causes of dementia.

Dementia symptoms may improve with treatment. But many of the diseases that cause dementia aren’t curable.

Dementia Causes and Risk Factors

The most common causes of dementia include:

Certain physical and lifestyle factors can put you at higher risk of having dementia,  including:

Certain physical and lifestyle factors can put you at higher risk of having dementia,  including:

  • Age
  • Dementia in your family
  • Illnesses including diabetes, Down syndrome, heart disease, and sleep apnea
  • Depression
  • Smoking, heavy alcohol use, poor diet, and lack of exercise

The Three Stages of Dementia

After dementia is diagnosed, it may follow a three-stage, downward trajectory.

Caregivers have an important role in easing that progression.


In mild dementia, people may have difficulty remembering words and names, learning and remembering new information, and planning and managing complicated activities such as driving. They may also be experiencing sadness, anxiety, loss of interest in once pleasurable activities, and other symptoms of major depression.


In moderate dementia, judgment, physical function, and sensory processing are typically affected. This can cause problems with personal hygiene, inappropriate language, and wandering. This stage — when your loved one is able to get around but has poor judgment — is physically and emotionally challenging for the caregiver. “My dad went from being Mr. Nice Guy to Mr. Obsessed. And things were always worse at night. He was energized and I was physically exhausted,” says Robert Matsuda, a Los Angeles musician who worked full-time and cared for his father with Alzheimer’s Disease for three years before recently placing him in a nursing home. As a patient moves from mild to moderate dementia, some home modifications that may include removal of throw rugs, installation of locks and safety latches, and the addition of a commode in the bedroom often need to be made.


This is also the time when the palliative care team should be brought in to support the caregiver and help manage behaviors. “I was anxious at first, but when they showed me how to manage my dad’s behaviors and started bringing services into our home — the nurse, the home health aide — it was like the cavalry arrived,” says Matsuda. In severe dementia, there may be extensive memory loss, limited or no mobility, difficulty swallowing, and bowel and bladder control issues. There may be a need for around-the-clock care. At this stage, the patient may have difficulty recognizing family members and caregivers.

Caregivers experiencing high stress levels during the moderate and severe stages may also be dealing with anticipatory grief associated with a feeling of impending loss of their loved one. Talking with the palliative care team’s social worker can help caregivers understand these feelings and develop strategies for dealing with them.

Experts warn that caregivers who do not get such help may be more likely to experience a prolonged, complicated period of grief after their loved one dies.


Oasis We Care provides assistance in most aspect of the education and care needed by offering resources in many aspects of the care as well as spiritual support.