Signs and Symptoms of Dementia

James M. Ellison, MD, MPH

Swank Center for Memory Care and Geriatric Consultation, ChristianaCare

  • Expert Advice
Published on:
A senior man pointing at a wall calendar and looking confused.

Learn how healthcare providers rely upon signs and symptoms to detect and assess dementia.

Edna got up from lunch and was about to leave the coffee shop without her umbrella. Her friend, Alma, handed it to her. “You’re going to need this – it’s still pouring!”

Edna looked upset. “This has been happening too often lately. I spent half the morning looking for my keys! I’m only 67, but you know my mother had Alzheimer’s disease by the time she was 75. I wonder if this is just a ‘senior moment’ or something more serious. I’m going to ask my primary care clinician about this.”

*The name and details were changed to protect privacy.

Signs and Symptoms: What are They?


Symptoms are subjective reports like “My back hurts,” or “I can’t concentrate,” or “I keep forgetting things.” As with Edna, symptoms lead people to seek advice and help. Symptoms are important, but they are not specifically linked to a disease—most common symptoms can suggest a variety of possible diseases or sometimes no disease at all. Some diseases occur without symptoms, such as the early stage of high blood pressure. During the examination, a clinician asks about symptoms and then searches for signs.


Signs of disease are measurable, objective signals that something is wrong. Swelling, redness, or rashes are signs. Elevated blood pressure is a sign. When we are discussing dementia, some of the important signs seen in a mental assessment are disorientation, difficulty recalling a list of words, trouble following a short set of instructions, inability to write a complete sentence, or failure to copy a geometrical figure. Physical and laboratory assessments add further information. A specific type of dementia may be more easily diagnosed, sometimes, when physical symptoms such as gait disturbance, tremor, or abnormal reflexes are present—or when brain imaging or laboratory tests show specific abnormalities.

Signs and Symptoms of Dementia

Alzheimer’s disease is the most common type of dementia, but there are other types as well.

The development of dementia usually has three stages.

Stage 1

First, there is a period during which a disease is developing but no symptoms are present, and signs are limited or absent if they are sought. Special lab or imaging tests are not used at this stage except in research, but some investigators think that risk for later dementia may already be detectable at this stage. This “asymptomatic phase” can last for years. Dementia related to a stroke, head injury, or other acute damage to the brain skips both the first and second stages.

Stage 2

During the next stage for most dementias, symptoms emerge but they are not yet severe enough to be called dementia. This is the stage called “mild cognitive impairment” or “mild neurocognitive disorder.”

During this phase, which again can last for years, a person may complain of difficulties including problems with focusing, trouble remembering recent events in detail, misplacing or losing things more often, more inconsistency about following up on appointments or tasks, or more trouble learning new things. A key feature of mild cognitive impairment is the need to compensate for cognitive changes with new behaviors such as increased reminders and lists. In this phase, brain changes can be detected at this stage by neuropsychological tests, brain imaging tests, and biochemical tests on blood or spinal fluid. People with mild cognitive impairment continue to function normally in most ways, though they and those close to them may be aware that there is a problem.

Edna, like so many older adults, experienced mild symptoms and she worried that they were the sign of serious disease on its way. However, it is very important to remember that mild cognitive symptoms can also be a part of normal aging. When symptoms such as concern about memory bring a worried person to their health care provider, assessment of symptoms and signs can often allay concerns or identify health and lifestyle factors that should be addressed to improve cognitive health.  Symptoms are nonspecific, so they can be misleading and cause unnecessary worry. Symptoms of forgetfulness, for example, might represent anxiety, depression, sleep problems, medication effects, or anything out of a long list of medical problems.

Stage 3

At the final stage, clinical dementia, a person’s cognitive problems are often very apparent to everyone. A person with dementia, by definition, is no longer able to live independently because of difficulties with memory, problem solving, or other cognitive functions that independence requires. At this stage, many people do not complain of symptoms. Their cognitive deficits may be invisible to them even though others are very aware of their impairment.

Signs of dementia include objective difficulty on tests of:

  • complex attention
  • orientation
  • memory and learning
  • language expression and comprehension
  • perceptual-motor function (the ability to coordinate muscle groups to accomplish a task)
  • executive function (the ability to reason and solve problems)
  • social cognition (the ability to recognize the meaning of others’ facial expressions and behavior so that we can interact successfully)

Physical examination may reveal changes in neurological (brain) functioning that accompany cognitive decline, for example when dementia has followed a stroke that causes weakness of an arm and leg. Additional signs may be identified through neuropsychological testing, i.e., of functions such as impaired memory, language, or motor coordination; neuroimaging (brain images); and blood tests.

Edna sought consultation from her primary care clinician. In her case, it was helpful to reduce the sleeping pills that she had recently started using and to find behavioral approaches to helping her get to sleep. Several weeks after she stopped using sleeping pills, she noticed a significant improvement in her concentration, focus, and memory.

(To navigate the table below on mobile devices, swipe left to see all of the columns.)

Now that we have reviewed the difference between signs and symptoms and have discussed the three stages of dementia, here is a chart of some common signs and symptoms at each stage:

Normal cognitive aging Inconsequential forgetfulness, slower learning, greater difficulty with multitasking Minimal changes are found on neuropsychological testing and brain imaging.
Pre-symptomatic stage No symptoms (by definition) Characteristic but mild changes on neuropsychological testing, brain imaging, or research tests of blood and cerebrospinal fluid may reveal increased dementia risk.
Mild cognitive impairment “Senior moments,” changes in memory, problem-solving, word finding, understanding, concentration, judgment, and mood are noticeable to the affected person and severe enough to require the development of new habits, but not so severe as to limit independence. Characteristic changes on neuropsychological testing, brain imaging, or research tests of blood and cerebrospinal fluid are more significant.
Clinical dementia Complaints of confusion that interferes with the following:

- completing tasks


- memory difficulty that disrupts daily function

- executive function impairment that shows itself in diminished problem-solving ability

- trouble understanding spatial relationships that can lead to getting lost

- language problems that interfere with naming, word-finding, or comprehension

- impaired judgment that can result in risky decision-making or behavior

- complaints of mood and personality changes such as anxiety, depression, anger, fatigue, fears of persecution

- sensory disturbances such as hallucinations may also occur.

At this stage, the focus usually shifts from symptoms to signs as the person’s awareness of deficits diminishes.


Significant to severe changes on neuropsychological testing (impaired memory, executive function, language, motor perceptual functioning, etc.), brain imaging, and tests of blood and cerebrospinal fluid in some cases.


About the author

Headshot of Dr. James Ellison

James M. Ellison, MD, MPH

Swank Center for Memory Care and Geriatric Consultation, ChristianaCare

James Ellison, MD received his medical degree from UCSF in 1978 and trained in psychiatry at the Massachusetts General Hospital (1979-1982).

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