Dementia Causes, Signs, Symptoms & Side Effects

No one experiences dementia the same way as someone else. Understanding the signs, symptoms and side effects of dementia is a key component toward starting the recovery journey.

Understanding Dementia

Learn about dementia

Dementia is the progressive decline of mental functions such as memory, the ability to reason, and the capacity to think that is so extreme it affects all areas of a person’s life. As dementia itself is a group of symptoms rather than a disease, it can be caused by illnesses, genetic diseases, medications, hormone imbalances, and other conditions. Alzheimer’s disease comprises 60-80% of causes of dementia. Vascular dementia is caused by a stroke and is the second most common type of dementia. While historically considered part of the aging process, we now know that the serious mental decline associated with dementia is not a normal part of aging.

Dementia is caused by damage to the cells in the brain, which can prevent the brain cells from properly communicating. When damaged brain cells cannot communicate in a normal manner behaviors, thinking, and emotions are affected. The human brain has different regions designed to carry out different functions and when certain brain cells are damaged typical functions are unable to be performed properly. The different types of dementia are correlated with the areas of the brain that are damaged.

There are over fifty causes for dementia, approximately 20% of which can be partially treated or cured, which means that early detection and treatment may be able to reverse this condition.


Dementia statistics

The overall prevalence of dementia varies wildly by age and the type of dementia a person has been diagnosed with. The prevalence of dementia increases dramatically from age 60 onward. It’s estimated that between 1-2% of people at 65 years of age have some form of dementia, while at 85 years of age, the prevalence of dementia is closer to 30%.

Causes and Risk Factors

Causes and risk factors for dementia

There are over fifty causes for dementia, some of which are reversible, however many of the causes for dementia are not. Some of the causes for dementia include:

Genetics: The strongest risk factor for both mild and major dementia is age, as age increases the risks for the risks for both neurodegenerative and cerebrovascular diseases. A family history of dementia can put you at a greater risk for developing dementia. Other genetic causes for dementia include:

  • Alzheimer’s disease: The most common form of dementia is Alzheimer’s disease, which accounts for between 60 and 80 percent of all diagnosed cases of dementia. Alzheimer’s disease is marked by stages of the disease – mild, moderate, severe – and symptoms may begin with an inability to remember names and recent events, followed by impaired judgment and behavioral changes, and finally challenges walking and swallowing.
  • Huntington’s disease: a genetic, progressive brain disorder that leads to abnormal involuntary movements, marked decline in reasoning and thinking skills, irritability, depression, and other behavioral changes.
  • Parkinson’s disease: as Parkinson’s disease is a progressive disorder, the later stages often result in progressive dementia.

Biological: There are a great number of biological reasons in which a person develops dementia. Some of the most widely seen are:

  • Vascular dementia: The brain, like the rest of the body, relies heavily on the supply of blood to the delicate tissues. Any cardiovascular problems, such as high cholesterol, that can cause damage to these blood vessels and deny the brain cells of oxygen can lead to dementia. Vascular dementia occurs after the brain has experienced a stroke, or a blood clot, cutting off the flow of blood to certain areas of the brain. The hallmarks of vascular dementia include impaired judgment and the inability to plan for the events needed to finish a task, although it’s worth noting that the location of the injury caused by the stroke does affect the types of impairment a person may experience.
  • Nutritional deficiencies and hormone imbalances may lead to certain types of dementia.
  • Normal Pressure Hydrocephalus: a build-up of fluid in the brain can lead to challenges with movement as well as memory loss.
  • Lewy-Body Dementia: While many of the symptoms of dementia with Lewy bodies are similar to those of the symptoms of Alzheimer’s disease, this disease can include sleep disturbances, visual hallucinations, as well as muscular rigidity.
  • Mixed Dementia: this condition occurs when more than one type of dementia exists in the brain.
  • Frontotemporal dementia: this dementia involves the nerve cells in the front and side parts of the brain and can cause changes in personality, behavior, as well as challenges using language.
  • Hypoxia: when the brain (and the rest of the body’s tissues) are deprived of oxygen for a period of time, due to a heart attack, asthma attack, or allergic reaction, dementia-like symptoms can appear. Dependent upon the length of time and area of the brain deprived of oxygen, hypoxic brain injury may be reversible.
  • Brain tumors: rarely, dementia is caused by damage from a tumor in the brain, and will cause symptoms related to the area of the brain that is affected.

Environmental: There are a number of environmental causes for dementia, which can include toxic reactions to substance abuse. Other environmental causes of dementia can include:

  • Traumatic brain injuries: one major head injury or smaller, chronic injuries (such as those associated with boxing or other contact sports) can also cause dementia, or dementia-like symptoms.
  • Infections or diseases: whether inherited or acquired, these can cause degeneration of the nerve cells of the brain leading to dementia.
  • HIV-Associated Dementia: the HIV virus, which causes AIDS, destroys brain cells and in its later stages, can cause memory problems, problems with concentration, and movement disorders.
  • Creutzfeldt-Jakob disease: also known as “Mad Cow Disease,” this rare brain disorder can occur in individuals without any risk factors for dementia. Creutzfeldt-Jakob disease may be inherited or caused by exposure to diseased tissue from the brain or central nervous system.
  • Poisoning: exposure to heavy metals like lead, pesticides, or other poisons can lead to dementia-like symptoms.
  • Adverse medication reactions: this reversible type of dementia, due to the adverse reaction to a single medication or a combination of medications can lead to dementia-like symptoms and may be reversible.

Psychological: Addiction to illegal, recreational substances, especially long-term alcohol use, can lead to certain types of dementia.

  • Wernicke-Korsakoff Syndrome: this chronic memory disorder is caused by a marked lack of Vitamin B-1, often caused by alcohol abuse, causes extreme problems with memory while leaving other cognitive faculties unaffected.

Signs and Symptoms

Signs and symptoms of dementia

As dementia is a group of disorders, the symptoms can vary wildly, even among those who have the same root cause. At least two of the following areas must be severe enough to cause significant impairment in activities of daily living: increased inability to communicate and use language, impairment in judgment and reasoning, abnormal changes in visual perception, decreasing ability to focus and pay attention, or memory impairment.

Other symptoms may include and often worsen over time:

Mood symptoms

  • Agitation
  • Anxiety
  • Feeling restless
  • Feeling depressed
  • Feeling withdrawn and socially isolated
  • Confusion about who you are and where you are
  • Inability to always remember loved ones.
  • Feeling frustrated with yourself and others

Behavioral symptoms

  • Problems with short-term memory, such as recalling appointments or locating car keys
  • Challenges carrying out routine tasks
  • Placing items in abnormal areas of the house and being unable to locate these possessions
  • Difficulties with tasks that require many steps even if previously performed
  • Challenges with planning and organization
  • Changes in personality

Physical symptoms

  • Challenges interpreting visual images
  • Problems judging distance
  • Problems with planning or solving problems
  • Difficulties with communicating with other people or making needs known
  • Inappropriate behaviors
  • Problems with motor functions and coordination

Psychological symptoms

  • Finding it hard to use logic and reasoning skills
  • Paranoia, the fixed and immutable believe that someone or something is out to get you and not believing anyone who says otherwise.
  • Hallucinations


Effects of dementia

Dementia is a group of diseases that tend to become progressively more severe over time and can severely impact your ability to carry out normal daily activities. Some of the effects of dementia can include:

  • Depression
  • Difficulties with communication
  • Emotional health deterioration
  • Hallucinations and delusions
  • Improper nutrition
  • Decrease in safety awareness
  • Cognitive decline
  • Memory decline
  • Changes in sleeping patterns
  • Inability to care for self
  • Inability to live independently

Co-Occurring Disorders

Dementia and co-occurring disorders

As dementia is not a single disease, rather a group of diseases, there are a number of co-occurring disorders. While not an inclusive list, these disorders can include:

  • Alzheimer’s disease
  • Vascular disease
  • Cardiovascular disease
  • Alcohol abuse
  • Huntington’s disease
  • Traumatic brain injury
  • Normal Pressure hydrocephalus
  • Creutzfeldt-Jakob disease
  • Wernicke-Korsakoff syndrome