Dementia is a decline in cognitive functions such as thinking, memory, orientation, reasoning, and decision-making that significantly interferes with a person’s daily life and independence. As dementia progresses, individuals may struggle with routine activities, communication, planning, and understanding situations appropriately.
In many cases, dementia is accompanied by changes in emotional control, mood swings, behavioral alterations, and personality changes. The condition progresses gradually—from a mild stage, where symptoms are subtle, to a severe stage in which a person becomes fully dependent on others for basic daily activities such as eating or dressing.
Millions of people worldwide live with dementia, and the risk increases with age. Approximately one-third of people aged 85 and older may have some form of dementia. However, dementia is not a normal or inevitable part of aging. Many people live well into their 90s without any signs of cognitive impairment.
There are several types of dementia, the most common being Alzheimer’s disease.
Dementia symptoms occur when healthy brain neurons (nerve cells) lose their connections or die. While some neuron loss is a normal part of aging, people with dementia experience a much greater degree of neuronal damage.
Common signs and symptoms include:
memory loss, impaired judgment, and confusion;
difficulty speaking, understanding language, reading, or writing;
wandering and getting lost in familiar places;
difficulty managing finances or paying bills;
repeating questions or statements;
using unusual or incorrect words for familiar objects;
taking longer to complete everyday tasks;
loss of interest in normal daily activities;
hallucinations, delusions, or paranoia;
impulsive behavior and reduced empathy;
balance problems and movement difficulties.
In individuals with intellectual or developmental disabilities, recognizing dementia symptoms can be particularly challenging. Monitoring changes in abilities and behavior over time is essential.
Dementia results from damage to or changes in specific areas of the brain that affect neurons and their connections. Researchers have linked certain types of dementia to abnormal protein accumulation or impaired blood flow in the brain.
Some conditions, such as adverse drug reactions or vitamin deficiencies, may mimic dementia symptoms. These causes can sometimes be reversed with appropriate treatment.
Alzheimer’s disease
The most common cause of dementia. It is characterized by the accumulation of beta-amyloid plaques and tau protein tangles in the brain, which damage neurons and disrupt communication between brain cells.
Vascular dementia
Caused by damage to blood vessels supplying the brain, often due to strokes or chronic vascular conditions. Typical symptoms include slowed thinking, difficulty with problem-solving, and impaired attention rather than early memory loss.
Lewy body dementia
Associated with abnormal protein deposits known as Lewy bodies. Common symptoms include visual hallucinations, fluctuations in attention, sleep disturbances, and Parkinson-like movement problems.
Frontotemporal dementia
A group of disorders involving degeneration of nerve cells in the frontal and temporal lobes, affecting personality, behavior, language, and movement.
Mixed dementia
A combination of two or more types of dementia, most commonly Alzheimer’s disease alongside vascular dementia or Lewy body dementia, especially in older adults.
Huntington’s disease
A genetic disorder that leads to progressive degeneration of nerve cells, typically presenting cognitive decline between the ages of 30 and 40.
Traumatic brain injury (TBI)
Repeated head injuries, common among athletes or military personnel, can increase the risk of dementia later in life.
Creutzfeldt-Jakob disease
A rare, fatal brain disorder caused by abnormal infectious proteins called prions, usually developing after age 60.
Parkinson’s disease dementia
Many individuals with Parkinson’s disease eventually develop dementia symptoms as the condition progresses.
To diagnose dementia, a physician first evaluates whether symptoms may be caused by treatable conditions. Diagnosis typically includes:
medical and family history review;
physical and neurological examination;
cognitive and neuropsychological testing;
blood tests to assess metabolic, hormonal, or vitamin imbalances;
brain imaging (CT, MRI, PET scans);
psychiatric evaluation when mood or behavior changes are present;
in selected cases, genetic testing or cerebrospinal fluid (CSF) analysis.
Early diagnosis is crucial, as some causes of cognitive impairment can be treated or managed more effectively when detected early.
increasing age;
family history and genetic predisposition;
Down syndrome.
Although there is no guaranteed way to prevent dementia, certain lifestyle measures may help reduce risk:
maintaining mental activity through reading, puzzles, and learning;
regular physical exercise and social engagement;
quitting smoking;
following a healthy diet, such as the Mediterranean diet;
ensuring adequate sleep;
managing cardiovascular risk factors (high blood pressure, diabetes, high cholesterol);
treating depression and anxiety;
addressing hearing loss early.
