What Causes Aggression in People with Dementia?

People with dementia face progressive cognitive decline and ongoing functional challenges. Many caregivers are family members, and they may encounter aggression such as shouting, swearing, hitting, or throwing things. Managing current behavior or preventing future incidents may be possible when caregivers understand the causes and warning signs.

Possible causes of aggression

Someone with aggressive behavior might be responding to something confusing or challenging in their environment. This behavior may emerge in the middle stages of dementia and is sometimes called “responsive behavior.” Contacting your medical practitioner is always advisable if there are concerns with new or continuing behaviors, as there may be a treatable medical cause.

Here are some common physical and emotional causes of aggressive behavior with quick tips for management.

Physical causes of aggressive behavior


People in the early stages of dementia may be able to inform their caregivers that they have discomfort. However, as dementia progresses, they may lose that ability to communicate, causing them to act out aggressively when they are in pain.

Quick tips:

  • Be aware of your loved one's facial expressions and body language that may indicate pain.
  • If you know your loved one has a history of arthritis or dental pain, you can manage their discomfort before it becomes uncontrollable.
  • Contact your medical practitioner if your strategies cannot address your loved one's pain.


When an older adult presents with a sudden onset of confusion, a urinary tract infection (UTI) may be responsible. Sometimes referred to as a “bladder infection," this disorder can cause a person with dementia to behave aggressively. In addition, symptoms such as frequent urination or pelvic discomfort may be upsetting.

Quick tips:

  • Older adults can be prone to UTIs when they do not have adequate fluid intake.
  • Encourage fluids by offering drinks while limiting coffee and tea. Also, provide water-based foods like Jell-O or watermelon.
  • Contact your medical practitioner if you suspect your loved one has a UTI, as they may need to be treated with an antibiotic.


A person with dementia who has bladder or bowel incontinence may have responsive behaviors. Incontinence products and soiled clothing can be embarrassing and uncomfortable.

Quick tips:

  • Check the state of clothing or incontinence products and change as needed.
  • Encourage regular trips to the bathroom to reduce incidents.
  • Don’t reduce fluid intake to manage incontinence, as dehydration may cause more severe health issues for your loved one.


When a person has constipation, it can cause abdominal discomfort, nausea, or vomiting. In a person with dementia, this discomfort can contribute to aggressive behavior.

Quick tips:

  • Provide a diet rich in fluids, fruit, and fiber to reduce incidents of constipation.
  • Ensure that you track the frequency of bowel movements to be alert to any changes.
  • Contact your medical practitioner in case your loved one may need a laxative or stool softener.

Hunger and thirst

A person with dementia is at risk of reduced dietary and fluid intake, causing hunger and thirst. In response to being unable to express this need effectively, they may behave aggressively.

Quick tips:

  • Offer and set out healthy snacks, finger foods, and drinks for your loved one throughout the day.
  • Also, add foods like Jell-O, watermelon, flavored water, or soup to increase fluid intake.


People with dementia can have altered sleep patterns due to disturbances in the sleep-wake cycle. Difficulty falling asleep or waking at night can contribute to fatigue throughout the day. Experiencing fatigue can also cause increased aggressive behaviors.

Quick tips:

  • Organize activity early in the day (or when your loved one is most alert).
  • Ensure a quiet environment in the afternoon and evening.
  • Practice good “sleep hygiene,” such as going to bed at a set time each night, exercising during the day, and reducing or eliminating caffeine intake.
  • Make sure the bedroom is dark and quiet at night.


Adverse effects and interactions of drugs can also contribute to aggressive behavior in people with dementia. It may also be caused by missing a dose or taking too many medications.

Quick tips:

  • Contact your medical practitioner or pharmacist for a medication review to identify problems.
  • Consistency can be tracked by packaging medications in a compliance system.

Emotional causes of aggressive behavior


Loneliness and depression may be sources of increased aggressive behavior in response to feelings of despair. During the pandemic, older adults with cognitive decline were more isolated, which increased depression.

Quick tips:

  • Provide activities for your loved one or involve them in an adult day program to increase engagement and improve mood.
  • Always ensure your medical practitioner is aware of any new or continuing mood concerns so proper treatment can be initiated.


A person with dementia can have stress, fear, and anxiety due to increased activity or a noisy environment. The overload of their senses may contribute to aggressive behaviors.

Quick tips:

  • Ensure a peaceful environment by speaking quietly, reducing stimulation, or playing quiet music.
  • Instructions should be written in an easy-to-understand manner.
  • Approach your loved one again later if he or she is resisting care.
  • Allow the person with dementia to keep as much control in their life as possible.


The loss of previously enjoyed activities may result from the progression of dementia. People may lose the ability to perform tasks once second nature to them. For example, losing the ability to drive a car can be most distressing, causing the person with dementia to respond aggressively.

Quick tips:

  • Redirect your loved one to another activity they enjoy and can manage well.
  • Validate your loved one's feelings of loss and avoid debating the issues.
  • The person with dementia may forget that they are unable to drive. Often families must keep keys out of sight, disable the vehicle or remove the car from the property.


Caring for someone with dementia may be challenging, especially if they exhibit aggressive behaviors. It is imperative to consult with your medical practitioner for diagnosis and treatment. You can also contact organizations like the Alzheimer Association to provide support and education for you and your loved one.

Key takeaways

People with dementia may have challenges expressing how they feel.

Aggressive or “responsive” behavior occurs in response to an unmet need.

Physical and emotional triggers such as pain, discomfort, and depression may cause aggressive behaviors.

Recognizing and acting on the warning signs may help to correct the cause and avoid aggressive behavior.

Knowing how to prevent the causes will reduce or prevent future incidents and provide a better sense of well-being for everyone involved.


Journal of Nursing Practitioners: Social Isolation in Dementia: The Effects of COVID-19

National Institute on Aging: Coping with Agitation and Aggression in Alzheimer's Disease

Alzheimer’s Association: Aggression and Anger

Alzheimer’s Association: Food and Eating

National Health Service (NHS): Coping with Dementia Behavior Changes

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