Changes in Behaviour

Dementia can affect a person’s behaviour. There can be many reasons for a change in behaviour, including changes in the brain, being in pain, change in routine, reduced capacity to communicate their needs or feeling misunderstood and not listened to.

You may sometimes find your loved one’s behaviour confusing, irritating or even upsetting. It can be challenging to know what to do or how to respond.


Remember, your loved one is not being difficult ...They can't help their behaviour


Understanding dementia and its impact on a person’s behaviour can help. The person may be in pain or discomfort – they may be constipated or thirsty or in pain from an infection such as a urinary tract infection (UTI) which can cause significant distress. Sitting or lying in one position and uncomfortable or tight clothes can lead to pressure sores. Other causes of pain include arthritis, headaches, foot problems, dental pain and osteoporosis. Some people can help you to do this.

Always discuss concerns about behaviour changes with your GP or consultant, who will be able to check whether there is a physical illness or discomfort present and provide some advice. They will help you to understand the behaviour and explore ways to help to deal with it. In some cases, there may be medications that can help to alleviate some symptoms. In other cases, there may be a reason for the behaviour, such as an undiagnosed infection which could be causing pain or discomfort.

Enjoy the time with your loved one and keep a sense of humour - it lightens some difficult situations!

Judy, Dublin.

Changes in behaviour during COVID-19

The current Covid-19 outbreak means many of our usual routines have been disrupted which may affect behaviours in a person with dementia. There are things that you and the person with dementia can do to help them to meet their needs and reduce the risk of changes in behaviour. For example:

  • Short simple sentences when explaining Covid-19 and why certain services are closed.
  • Answer their questions using their words.
  • Speak in a calm, clear voice.
  • Maintain a structured daily routine and activities.
  • Limit listening to news bulletins. Hearing about the pandemic repeatedly can be upsetting.
  • Try to remain calm, try not to raise the alarm about the virus to the person you care for and limit what you say about Covid-19.
  • Daily walks outside when possible.
  • Gentle exercises at home.

Even though a person with dementia may have difficulties with their memory, they still retain emotions. This means they are more likely to respond to the emotional aspects of a situation. It’s essential to consider how they feel, what they are trying to express, and how to support their emotions. It may help to validate the person’s feelings, for example, ‘I can see that this is difficult for you.’.

To read more, download our factsheet – Practical tips for changes in behaviour

It is also vital to look after yourself, as everyone caring for someone with dementia needs support and people with whom they can discuss their problems and feelings.

Talking to someone can help. Bottling up your feelings or not taking the time to address them is likely to make things worse. You can speak in confidence to our Helpline by calling 1800 341 341, emailing [email protected] or via Live Chat at

For more practical tips, you can also visit our webpage for carers on Looking after yourself.

The doctor working with you and your loved one must know about behaviours that emerge and works with you and your loved one to understand and deal with them.

Our fact sheets will help you understand and cope with some behaviours that can emerge when a person has dementia. Not every person with dementia will experience all these behaviours; choose the ones you feel are relevant to you.

Read and download our factsheet:

If you want printed copies of these factsheets, contact our national Helpline at 1800 341 341 or email [email protected]. We post copies free of charge to family members and friends of people with dementia.

This video explains how brain parts can become damaged, resulting in changes in behaviours that may be difficult to understand and deal with.

Agitation and frustration

Agitation is a mix of anxiety and restlessness. Anxiety is a natural reaction to threats or fears. These could be real or imagined. When you feel anxious, your heart beats faster, and you may feel out of breath. When anxiety reaches a certain level, you can experience restlessness and feel unable to stay still. This mix of anxiety and restlessness is known as agitation.

When a person with dementia feels agitated, they cannot rest or stay still. They feel they have to move. At these times, it can be challenging for a person to understand what’s happening to them, and it can become challenging to deal with. When someone is agitated, they experience a high-stress level, and their quality of life can decrease. They may feel they have less control and can’t enjoy what they’re doing. Agitation feels awful and can hurt every aspect of their life.

Your Feelings

You mustn’t blame yourself if what you try does not work. It is also important to remember that caregivers can experience anxiety and frustration too. As a person’s mental state constantly changes, there may be no perfect solution that works every time. If necessary, contact specialist advisors, particularly if the behaviour becomes intolerable. In this case, talk with their doctor as they may need anti-anxiety medication on a short-term basis. This can help reduce a person’s agitation and allow the usual reassuring activities to work.

For more information, view and download our factsheet on Agitation and Frustration by clicking here or call our Helpline on 1800 341 341 to order a copy to be posted free of charge.


Hallucinations are sensory experiences that don’t exist outside a person’s mind. This means that a person hallucinates and can see, hear, smell, taste or feel something that isn’t there. People with dementia sometimes experience hallucinations. These can have many causes:

  • Dementia can cause physical changes to the brain.
  • Certain types of dementia tend to cause persistent visual hallucinations (such as Lewy body dementia).
  • Some illnesses (such as infections) may cause hallucinations or worsen them.
  • Side effects of some medications may include hallucinations. Dementia may worsen a pre-existing mental health condition that already causes hallucinations.

What you can do if you think a person is experiencing hallucinations?

First, make sure it is a hallucination, not a real event. Secondly, make sure that you seek medical advice. Then, ask yourself the following questions:

  • Is the person scared or distressed by the experience? If not, then hallucinating may not be a big issue for them.
  • Is the person aware that the experience is not real?
  • Do the hallucinations put the person, or anyone else,
    at risk?
  • Do the hallucinations happen at a particular time or in a particular place? (Keep a note of the hallucinations to see if there is a pattern.)

For more information on hallucinations, including visual hallucinations, auditory hallucinations, rare types of hallucinations, misidentification and misinterpretations, you can view and download our resource on Hallucinations by clicking here, or you can call our Helpline on 1800 341 341 to order a copy to be posted to you free of charge.

Dementia and Intimate Relationships

If you are caring for a partner with dementia, there will be many changes in your relationship over time, and these may include changes in your sexual relationship. Of course, every couple and each situation is different, but sexual problems, when they occur, can often be a cause of great distress.

You are likely to experience a sense of loss if an excellent sexual relationship ceases or no longer becomes enjoyable. It may help if you can express your feelings to a professional or a good friend rather than bottling your feelings. If you are part of a carers group, you could raise the issue at the next meeting to see how others in a similar situation have dealt with it. It is important to remember that any strange or uncharacteristic sexual behaviour is likely to be part of dementia and not directed at you personally.

Of course, this may not be an area of concern for you. You may be able to continue with a satisfying sexual relationship for quite a few years to come, or you may feel happy that you can remain affectionate and close in other ways.

Before the Diagnosis

You may become aware of somewhat puzzling changes in the period before dementia is diagnosed.

Perhaps your partner has become less interested in sex, and you feel hurt or rejected, or perhaps they have become more sexually active but less loving and considerate.

With a diagnosis of dementia, you can at least feel assured that nothing personal is involved and perhaps make allowances for changed behaviour. It may help to talk to your GP or other professionals about why dementia affects your partner’s sexual behaviour in a particular way.

Diminishing Sexual Interest

Many people with dementia do seem to lose interest in a sexual relationship, and the person may become entirely withdrawn at a reasonably early stage. Being stroked or cuddled may reassure them, but they may not be able to initiate any affection themselves.

Increased Sexual Demands

You may find that your partner’s desire for sex has increased, sometimes resulting in unreasonable and exhausting demands, often at odd times or in inappropriate places. This may make it difficult for you to show normal affection if your partner mistakes it for sexual advances.

Carers’ Reactions

Carers describe a wide range of feelings about continuing a sexual relationship with their partner, ranging from the pleasure that this is something which they can still share to distaste at being touched by someone who seems like a stranger. As the illness progresses, the situation often changes, and so do their feelings.

  • Some carers find it impossible to contemplate sex because they are caring for their partner as a parent might for a child. They find that intimate tasks they must do for the person put them off the idea of sex.
  • Many carers find it hard to enjoy a sexual relationship when so many other aspects of the relationship have changed, and little else is shared. They feel they are living with a different person.
  • Some carers find their partners clumsy and inconsiderate due to dementia, but they don’t want to undermine their confidence. Sex becomes something to be endured rather than enjoyed.

Carers often feel guilty about their reactions and need to talk to someone who understands the situation.

For Further Information:

If you want printed copies of these factsheets, contact our national Helpline at 1800 341 341 or email [email protected]. We post copies free of charge to family members and friends of people with dementia.

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