What Are the Symptoms of Dementia?

By Dr. Chirag Gupta

Dementia is an umbrella term for a group of brain disorders that cause a progressive decline in memory, thinking, behaviour and the ability to perform everyday activities. It is not a normal part of ageing — it represents changes in the brain that interfere with a person’s daily life and independence. Recognising the symptoms early helps families get the right diagnosis, support and treatment sooner. 

Dementia doesn’t look the same in everyone

One of the most important things to understand is that dementia is not a single disease. Alzheimer’s disease is the most common cause, but vascular dementia, Lewy body dementia, frontotemporal dementia and a range of other conditions can all produce dementia. The pattern of symptoms varies by the underlying cause and the brain regions affected — so two people with “dementia” can present very differently. 

Core symptom groups to watch for

Symptoms of dementia typically fall into several overlapping categories. Below are the common signs family members and caregivers often notice first.

1. Memory and learning problems (especially short-term memory)

One of the earliest and most recognized signs is difficulty remembering recent events, conversations or appointments while more distant memories remain intact. Repeatedly asking the same questions, relying on memory aids more than before, or forgetting recent visitors are typical early clues. However, memory loss alone does not automatically mean dementia — it’s the pattern and progression that matter.

2. Problems with thinking, planning and decision-making

People may struggle with complex tasks they previously managed easily — balancing a checkbook, following a recipe, planning an outing or managing medication. This decline in executive function shows up as poor judgment, slowed thinking, difficulty concentrating, or trouble finishing multi-step tasks. 

3. Language and communication difficulties

Finding the right words, following or joining conversations, and understanding written or spoken language can become harder. A person may repeat themselves, substitute wrong words, struggle to name familiar objects, or withdraw from discussions to avoid embarrassment. 

4. Disorientation with time and place; getting lost

People with dementia can become confused about dates, the time of day, or where they are. Getting lost on a previously familiar route or forgetting how they arrived somewhere are red flags that should prompt evaluation.

5. Changes in mood, personality and behaviour

Irritability, anxiety, apathy, depression, social withdrawal, mistrust or sudden mood swings are common. In some types of dementia (for example, frontotemporal dementia), personality change may be the earliest and most striking sign. Visual hallucinations or paranoid thinking are more typical of Lewy body dementia.

6. Difficulties with movement and coordination (sometimes)

Some forms of dementia cause motor symptoms such as slowed movement, tremor, stiffness or problems with balance and coordination. These symptoms are more prominent in conditions like Lewy body dementia or when vascular disease affects specific brain areas. 

7. Sleep and appetite changes, and incontinence in later stages

Sleep disturbances, changes in appetite or food preferences, and loss of bladder or bowel control may appear as dementia progresses. These changes often increase the need for caregiver support and safety planning. 

Subtle early signs people often miss

Dementia can begin quietly. Subtle clues include withdrawing from hobbies, losing interest in social activities, making unusual financial mistakes, reduced hygiene, or small but persistent changes in mood and motivation. Noticing patterns over time — rather than a single lapse — is key. 

When to see a doctor — red flags that need prompt attention

Make an appointment if you or a loved one has:

• Progressive memory loss or confusion affecting daily life;
   
• Repeatedly getting lost or disoriented;
   
• New personality or behaviour changes;
   
• Difficulty with speaking, walking, or controlling movement; or
   
• Symptoms that start suddenly or rapidly (this can indicate stroke, infection or other treatable causes).
  Early assessment can identify reversible causes (medication effects, vitamin deficiencies, thyroid problems, infections) and allow planning, treatment and support.
   

How dementia is diagnosed (briefly)

Diagnosis combines a careful history (including eyewitness accounts), a physical and neurological exam, cognitive testing, blood tests to rule out reversible causes, and brain imaging (usually MRI). Specialist testing such as neuropsychological assessment or biomarkers may be needed in complex cases. A timely, thorough evaluation helps identify the type of dementia and the most appropriate care plan. 

Practical next steps for families

1. Keep a symptom diary (when symptoms began, examples of changes, videos if possible).
    
2. Bring a trusted witness to medical appointments — clinicians rely on observations from family/friends.
    
3. Ask about reversible causes and safety planning (medication review, driving, finances, home hazards).
    
4. Explore support early — memory clinics, community dementia services and caregiver support make a big difference.
    

Dementia can be frightening, but early recognition, diagnosis and support change outcomes: they open the door to treatments, planning, and services that preserve quality of life. If you’ve noticed worrying signs in yourself or someone you love, don’t wait — a timely medical review is the first step.

— Dr. Chirag Gupta