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Alzheimer's disease symptoms

3-minute read

Many of the symptoms of Alzheimer's disease are similar to those of other conditions.

No two cases of Alzheimer's disease are ever the same because different people react in different ways to the condition. However, generally, there are 3 stages to the condition:

  • mild
  • moderate
  • severe.

Alzheimer's disease tends to 'creep up' on you, so you may not notice the symptoms immediately. However, the rate at which they progress will differ for each individual.

The 3 stages of Alzheimer's disease are described below.

Mild Alzheimer's disease

Common symptoms of mild Alzheimer's disease include:

  • confusion, for example about time or location
  • problems with short-term memory and forgetfulness
  • loss of interest or apathy
  • difficulty learning new things.

These symptoms are the result of a gradual loss of brain function. The first section of the brain to start deteriorating is often the part that controls the memory and speech functions.

Moderate Alzheimer's disease

As Alzheimer's disease develops into the moderate stage, it can also cause:

  • hallucinations – where you hear or see things that are not there
  • delusions – where you believe things that are untrue
  • obsessive or repetitive behaviour
  • lack of judgement
  • inappropriate behaviour
  • neglect of hygiene.

During the moderate stage, you may have difficulty remembering very recent things. Problems with language and speech could also start to develop at this stage. Worsening symptoms in the moderate stage of Alzheimer’s disease can cause you to feel very frustrated and depressed, and lead to mood swings.

Severe Alzheimer's disease

Someone with severe Alzheimer's disease may seem very disorientated and show signs of major confusion.

This is also the stage where people are most likely to experience hallucinations and delusions. They may think that they can smell, see or hear things that are not there, or believe that someone has stolen from them or attacked them when they have not. This can be distressing for friends and family, as well as for the person with Alzheimer's disease.

The hallucinations and delusions are often worse at night, and the person with Alzheimer's disease may start to become violent, demanding and suspicious of those around them.

As Alzheimer's disease becomes severe, it can also cause a number of other symptoms such as:

  • sleep disorders
  • incontinence – where you unintentionally pass urine (urinary incontinence) or stools (faecal or bowel incontinence)
  • difficulty swallowing
  • difficulty changing position or moving from place to place without assistance
  • weight loss or loss of appetite
  • increased vulnerability to infection
  • significant loss of short-term and long-term memory.

During the severe stage of Alzheimer's disease, full-time care is needed.

Life expectancy

Alzheimer's disease affects a person's ability to look after themselves when they are unwell, so another health condition can develop rapidly if left untreated. A person with Alzheimer's may also be unable to tell someone if they feel unwell or uncomfortable.

Alzheimer's disease can shorten life expectancy. This is often caused by the development of another condition, such as pneumonia (infection of the lungs), as a result of having Alzheimer's disease. In many cases, Alzheimer's disease may not be the actual cause of death, but it can be a contributing factor.

Dementia decline - expert advice

When you have dementia it is important that the condition and your physical health are monitored closely. Conditions such as a bladder infection, the flu or cold or even changes in medication can cause a rapid deterioration of symptoms in dementia. Find out about other conditions that can affect dementia in the video below.


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Last reviewed: May 2017

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