Understanding the Basics of Dementia, and Tips on Reducing the Risks

Susy Santos, Ph.D., M.A.,
Director of Health Innovation

Although people typically associate dementia with memory loss such as forgetfulness, dementia is actually a term used to describe symptoms of diminished memory, communication and thinking which impacts daily life.  Dementia is caused by several diseases and is not a normal result of aging even though older people are most afflicted.  In Canadian adults aged 85 and over, 25% will be diagnosed with dementia and it is more prominent among women than men.

Dementia occurs because of brain cells dying; neurodegenerative disease, which causes brain cell death over time, causes most cases of dementia.  What is not known is whether brain cell death causes dementia or if this cell death is caused by dementia.  Strokes, damage from repetitive head injuries, brain tumors, prion disease, HIV infection and reversible factors such as depression or vitamin deficiency can all cause dementia. 

Here are five of the most common types of dementia:

  • Alzheimer’s Disease causes neurons in the brain to die and accounts for 60% of all dementia.
  • Vascular Dementia is the second most common cause of dementia and is caused by damage to the vessels carrying blood to the brain and the blood brain barrier, leading to neuronal death.  Most often there is a history of strokes, head injuries, diabetes, hypertension or smoking.
  • Lewy Body Dementia is a progressive disease characterized by clumps of abnormal protein in the brain called Lewy bodies.
  • Frontotemporal dementia is a group of diseases that cause the deterioration of nerve cells in the temporal and frontal brain lobes.
  • Mixed Dementia is when two or more types of dementia occur at the same time.

Dementia can be caused by other disorders.  Here are three of the most common conditions related to dementia:

  • Parkinson’s Disease is also characterized by Lewy bodies being present in the brain and many people with Parkinson’s develop dementia.
  • Creutzfeldt-Jakob disease is a rare condition in which the brain begins to break down and may be caused by abnormal proteins called prions.
  • Huntington’s disease is caused by a mutation in chromosome 4 that causes changes in the brain and spinal cord.

Dementia can be imperfectly divided into four different stages.  The first stage is mild cognitive impairment which is exemplified by forgetfulness.  The second stage is mild dementia, in which cognitive impairments begin to occur.  This can include confusion, changes in personality, loss of memory, and challenges with directions.  During moderate dementia, the third stage, individuals require additional help as day to day life becomes more difficult.  Although symptoms are similar to those seen during mild dementia, they are increased, quality of sleep decreases and significant personality changes occur.  In the fourth stage, severe dementia, individuals may no longer be able to communicate and will require full time care.

Recognizing the symptoms of dementia is important in order to determine whether they are due to treatable conditions (such as infections, nutritional deficiencies, or medication side effects) or other underlying conditions.  Some early signs are memory loss, confusion, disorientation, changes in mood and in short term memory, difficulty with communication, difficulty in accomplishing daily tasks and trouble with problem solving or accomplishing complex tasks.  Other psychological changes might be anxiety, depression, agitation, inappropriate behaviour, and paranoia.

There are a multitude of risk factors that can lead to dementia.  The risk factors that cannot be changed are age, family history and Down syndrome.  Risk factors that can be controlled are diet and exercise, heavy alcohol use, cardiovascular health, depression, diabetes, smoking, sleep apnea, and deficiencies in vitamins and nutrition. 

What can you do for your cognitive health?

Although there is no definitive way to prevent dementia, there are things that you can do to reduce your risk.  Stimulate your mind with puzzles, reading or memory training.  Be active which means increased exercise but also increased social interaction.  Quit smoking and reduce alcohol intake.  Make sure to maintain a healthy diet rich in fruits, vegetables and omega-3 fatty acids as well as plenty of vitamin D, B, and C.  Treat any cardiovascular risks such as high blood pressure as well as any other health conditions such as anxiety or depression.  Quality sleep is also essential.

The more preventative steps that you take during your 40s and 50s, the more likely you’ll lower the risk of developing dementia.


  1. Canadian Institute for Health Information. Dementia in Canada. Ottawa, ON: CIHI; 2018.
  2. Dementia. Mayo Clinic. Accessed August 2020 https://www.mayoclinic.org/diseases-conditions/dementia/symptoms-causes/syc-20352013
  3. Grossman M. An introduction to different types of dementia. Accessed August 2020 https://www.kindlycare.com/types-of-dementia/
  4. MacGill M. Dementia: Symptoms, stages and types. Medical News Today; 2017.
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