Aggressive behaviours

What are aggressive behaviours?

Changes in the behaviour of people with dementia are very common.

Sometimes this can include aggressive behaviours such as verbal abuse, verbal threats, hitting out, damaging property or physical violence towards another person. 

What causes these behaviours?

There are many reasons why behaviours change. Every person with dementia is an individual who will react to circumstances in their own way. Sometimes the behaviour may be related to changes taking place in the brain. In other instances, there may be events or factors in the environment triggering the behaviour. In some instances a task may be too complex. Or the person may not be feeling well. 

Understanding the behaviours

It is important to try to understand why the person with dementia is behaving in a particular way. If family members and carers can determine what may be triggering the behaviour, it may be easier to figure out ways to prevent the behaviour happening again.

Some frequent causes of agitated behaviours are outlined below:

Health issues

  • Fatigue
  • Disruption of sleep patterns causing sleep deprivation
  • Physical discomfort such as pain, fever, illness or constipation
  • Loss of control over behaviours due to the physical changes in the brain
  • Adverse side effects of medication
  • Impaired vision or hearing causing the person to misinterpret sight and sounds
  • Hallucinations.

Defensive behaviours

A person with dementia may feel humiliated because they are forced to accept help with intimate functions such as bathing. They may feel their independence and privacy are being threatened.

Sense of failure

Because they are no longer able to cope with everyday demands a person with dementia may feel pressured or frustrated.


No longer understanding what is going on may lead to bewilderment, or the person may become distressed by an awareness of their declining abilities.


The person with dementia may become frightened because they no longer recognise certain places or people. They may seek places that were familiar to them at an earlier time in their life or may be recalling an earlier life experience that is frightening or uncomfortable to remember.

Need for attention

A person with dementia may be trying to let someone know that they are bored, distressed, have an excess of energy or feel ill. 

What to try

To prevent aggressive behaviours

  • Always discuss concerns about aggressive behaviour with the doctor, who will be able to check out whether there is a physical illness or discomfort present, and provide some advice. The doctor will also be able to advise if there may be an underlying psychiatric illness or undesirable side-effects of medication
  • Be aware of the warning signs of aggression
  • Try to reduce the demands made on the person
  • Eliminate possible causes of stress
  • Ensure that there is an unrushed and consistent routine
  • Keep the environment consistent
  • Spend time explaining what is happening, step-by-step, in simple sentences. Even if the words are not understood your calm tones may be reassuring
  • Avoid confrontation. Either distract the person’s attention or suggest an alternative activity
  • Make sure the person gets enough exercise and participates in activities
  • Make sure they are comfortable.

Preventable measures may not always work. Do not blame yourself if the person still becomes aggressive. Concentrate on handling the situation as calmly and effectively as possible.

When aggressive behaviours occur:

  • Stay calm. Speak in a calm, reassuring voice
  • Address the underlying feeling if possible
  • A simple suggestion such as having a drink together, going for a walk or looking at a magazine together may help. Distraction and avoidance are often the most useful approaches
  • If you feel unsafe, stand out of reach. Closing in or trying to restrain the person, unless absolutely necessary, can make matters worse. You may need to leave them until they have calmed down
  • If you have developed some strategies for managing aggressive behaviours try to make sure that they are used by any other people who are also caring for the person with dementia.

Aggressive behaviours can be very difficult for families and carers. The behaviours are symptoms of dementia and are not meant to deliberately upset you. Remember to look after yourself and take regular breaks from caring.

Looking after yourself

  • Try to remain calm
  • If you do become frustrated or lose your temper, don’t feel guilty. But do regard it as a sign that you need some extra support. Talk it over with your doctor, a friend or a counsellor
  • Prepare a safe haven for yourself if aggressive behaviour is a problem. This can be a room which locks from the inside, preferably with a phone
  • It is not always easy to forget these incidents. They may leave you feeling quite shaky
  • Take regular breaks from caring.

Who can help?

Discuss with the doctor your concerns about behaviour changes and their impact on you.