Alzheimer’s and dementia — the differences explained

Dementia or Alzheimer's DiseaseThe terms Alzheimer’s disease and dementia are often used interchangeably. However, both terms refer to two different things.

What is dementia?

Dementia is the overall term for several symptoms related to a decline in cognitive (thinking) skills. Dementia is known as a symptom of disease, and not a normal part of ageing. There are over 100 diseases that cause dementia.

A quick glance at some statistics shows that:

  • by 2050, around 900,000 Australians are expected to suffer from dementia
  • each week 1,800 new cases are diagnosed, with this expected to increase to 7,400 by 2050
  • dementia is the second leading cause of death in Australia
  • 30 per cent of people over 85 years have it
  • there is no cure for dementia.

 Those with dementia can display a range of symptoms including, gradual loss of memory, problems with reasoning or judgement, disorientation, difficulty in learning, loss of language skills, and a reduced ability to perform everyday tasks.

Sufferers may also display changes in their behavior. They may become agitated, anxious, aggressive and may even suffer from delusions or hallucinations.

What is Alzheimer’s disease?

Alzheimer’s disease is a the most common cause of dementia. Pronounced AHLZ-hi-merz, this progressive disease of the brain was first described in 1906 by German physician Dr Alois Alzheimer.

There are two types of Alzheimer’s disease:

  • Sporadic Alzheimer’s disease — is the most common type of Alzheimer’s and usually occurs over the age of 65.
  • Familial Alzheimer’s disease — this is rare and is caused by a genetic mutation. Symptoms often appear from the age of 40 or 50 years.

Dementia or Alzheimer's diseaseWhile the exact cause of Alzheimer’s disease is not yet known, scientists believe that it may be caused by a combination of genetic, lifestyle and environmental factors that affect the brain over time.

Can Alzheimer’s disease and dementia be prevented?

While not all cases of Alzheimer’s disease are preventable, there are some risk factors. Some of them you can control and some of them you cannot.

Uncontrollable risk factors:

  • Age — your risk increases with age
  • Genetics — some forms of Alzheimer’s are related to genetic risk

Controllable risk factors

  • Brain activity — challenging your brain with mentally stimulating activities is associated with a lower risk, as is participating in social activities and being connected with others
  • Diet — a healthy diet (with low to moderate alcohol intake), is associated with better brain health
  • Physical activity — regular exercise promotes brain health and reduces the risk of cognitive decline and dementia
  • Weight — being obese in midlife increases your risk
  • Heart risk factors — untreated high blood pressure and a history of high cholesterol is associated with a greater risk of developing Alzheimer’s
  • Diabetes — developing type 2 diabetes midlife increases your risk
  • Smoking — smoking (including passive smoking) puts you at a higher risk

Get an early diagnosis

There is no doubt receiving a diagnosis of dementia can be difficult. However, the earlier a diagnosis is made, the easier it is for the patient and family to accept and begin to make plans for the future.

If you are concerned that you or a family member are showing signs of dementia, speak to your doctor as soon as possible.


Further information: Alzheimer’s Australia.