What's the difference between Alzheimer's and dementia?

Last updated:
Reviewed by:
Dr Bryony Henderson, Lead GP at Livi
Although there are similarities, Alzheimer’s disease and dementia are not the same. We take a closer look at how the conditions overlap, but also how they are managed and treated differently.

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In simple terms, dementia is used to describe symptoms that affect your memory, performance of daily activities and ability to communicate. Alzheimer’s disease is the most common type (and cause) of dementia, that gets progressively worse over time. Both are more common in adults over the age of 65, but are not considered a normal part of ageing.

What is dementia and the different types?

Dementia is the medical name for a group of cognitive symptoms including problems with memory, thought processing, problem solving, language and perception.

As well as Alzheimer’s disease, there are over 200 types of dementia, caused by a number of diseases that damage the brain by a loss of nerve cells. Other types of dementia include:

  • Vascular dementia – this happens when a lack of oxygen to the brain causes nerve cells to die, either from a stroke, a series of mini strokes or a disease of the small blood vessels in the brain
  • Mixed dementia – this diagnosis occurs when someone has more than one type of dementia and a combination of symptoms
  • Dementia with Lewy bodies – this occurs where abnormal structures (known as Lewy bodies) form in the brain and cause nerve cells to die
  • Frontotemporal dementia – this is where clumps of abnormal protein form in the front and side of the brain and cause nerve cells to die

What is Alzheimer’s disease?

Alzheimer’s disease is the most common cause of dementia (and is responsible for 60 to 80% of dementia cases) and usually begins gradually with mild symptoms of memory loss. This can lead to other cognitive problems like struggling to recall recent events or learn new information. People affected by Alzheimer’s disease can also have trouble finding the right words and making decisions.

Alzheimer’s disease is caused by a build up of abnormal structures known as plaques or tangles. These affect how nerve cells function in the brain and eventually cause them to die. The disease also causes a shortage of some important chemicals in the brain which mean that messages are not able to travel around as well as they should.

As Alzheimer’s disease progresses over time, the associated problems will become more severe, which will mean the person needs more day-to-day support.

What are the key symptoms of Alzheimer’s and dementia?

There are several overlapping symptoms of Alzheimer’s and dementia, but there are also some differences. The symptoms of someone with dementia depends on which parts of the brain are damaged, and the disease causing the dementia. Both conditions can cause:

  • Impaired memory
  • Impaired communication
  • A decline in the ability to think

Some of the more specific symptoms of Alzheimer’s disease include:

  • Difficulty recalling conversations or activities
  • Impaired judgement
  • Disorientation
  • Confusion
  • Apathy
  • Depression
  • Changes in behaviour
  • Difficulty speaking, swallowing or walking

Certain types of dementia will share some of these symptoms. To be able to make a diagnosis, other symptoms must be included or excluded.

For example, Lewy body dementia (LBD) has lots of the same advanced symptoms as Alzheimer’s disease. People with LBD are more likely to experience initial symptoms such as visual hallucinations, difficulties with balance, and sleep disturbances.

Parkinson’s disease and Huntington’s disease can contribute different types of dementia symptoms in the early stages. These include involuntary body movements.

How are Alzheimer’s and dementia treated differently?

Treatment options for Alzheimer’s disease and dementia will depend on the exact cause and symptoms – but many treatments can be beneficial for both. There is currently no cure for Alzheimer’s disease, but there are various treatments available that can help manage the main symptoms. These include:

  • Medication for behavioural changes
  • Medications for memory loss
  • Alternative remedies to boost brain function and health such as coconut oil and fish oil
  • Medications for sleep problems
  • Medications for depression

There’s also no definitive cure for dementia but, in some cases, treating the exact cause can help relieve and manage the symptoms. Some of the conditions most likely to respond to treatment include dementia that is caused by:

  • Brain tumours
  • Drugs
  • Metabolic disorders
  • Hypoglycemia

Certain forms of dementia are more straightforward to treat. Doctors often prescribe a medication, cholinesterase inhibitors, for dementia caused by Parkinson’s disease, Alzheimer’s disease, and LBD.

For vascular dementia, treatment will focus on preventing further damage to the brain’s blood vessels and the risk of having a stroke.

People living with dementia can also benefit significantly from local support services, carers and health aids. As the disease progresses with time, it may be necessary for the person with dementia to move to an assisted living facility or nursing home.

What is the outlook for both – and which is worse?

Similarly to treatment options, the outlook for people with dementia depends on the cause. Treatments can make symptoms of dementia manageable.

Most types of dementia are irreversible and will cause more impairment over time. Vascular dementia can be slowed down in some cases, but it still shortens the affected person’s lifespan.

Alzheimer’s disease is considered a terminal illness, as there is currently no cure. People over 65 with the disease live an average of 4 to 8 years after receiving a diagnosis. But it’s also possible for some people to live as long as 20 years after being diagnosed.

If you have any concerns that you’re experiencing the symptoms of dementia or Alzheimer’s disease, it’s a good idea to talk to a doctor. They will make sure you get the right diagnosis, and if needed start taking treatment promptly to manage any symptoms.

How to help prevent dementia

While there’s no proven way to prevent dementia, lots of research is taking place to better understand how to reduce the risk factors. Certain risk factors for dementia are very difficult or impossible to control, such as:

  • Age – the older you are, the more likely you are to develop dementia
  • Genes – in general, genes alone are not thought to cause dementia. But certain genetic factors are involved with some of the less common types. Dementia usually develops because of a combination of genetic and environmental factors, such as smoking and a lack of regular exercise.

There are other risk factors that can be reduced including hearing loss, depression, loneliness and social isolation.

And there’s good evidence that making healthy lifestyle choices can help reduce your risk of developing dementia by around a third. These include:

  • Eating a healthy and balanced diet
  • Maintaining a healthy weight
  • Having a healthy blood pressure
  • Exercising regularly
  • Sticking to recommended alcohol limits
  • Stopping smoking

Choosing a healthy lifestyle helps prevent cardiovascular diseases too, such as stroke and heart attacks, which are both risk factors for the most common types of dementia (Alzheimer's disease and vascular dementia).

When to speak to a doctor

If you’re having problems with your memory or experiencing other symptoms of dementia, it’s best to speak to a doctor as soon as possible.

They can make a specialist referral if necessary, and provide you with more information. A doctor can also discuss ways to reduce your level of risk.

It can be very difficult to be given an Alzheimer’s disease or dementia diagnosis and can come as a shock to the person and those around them.

There’s plenty of help and support available, as well as treatments to help manage your symptoms.

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