Cognitive Health

Older Adults and Cognitive Health

What is dementia?

  • A brain disease.
  • Caused by damage and loss of nerve cells in the brain. Symptoms include disruption in recognition, memory, judgment, mathematics, language, problem solving and decision-making process.
  • Some people with dementia may experience changes in personality, behavior and psychosocial well-being.
  • The degradation of these functions affects daily life and activities, is not a normal part of aging.


  • A local report in 2017 stated that 1 in 10 older adults suffered from dementia in Hong Kong.
  • The prevalence of dementia increases with age to about 20-30% of the adults aged over 80 suffering from dementia of varying stages.


  • Alzheimer’s disease: the most common type (around 60-70%), which has a progressive onset. Its causes remained not fully identified.
  • Vascular dementia: the second most common type (around 20-30%), caused by reduced blood flow to the brain, e.g. stroke and other cerebrovascular diseases. Patients often have comorbidities such as hypertension, diabetes mellitus, hyperlipidemia, or obesity. 
  • Others: Parkinson’s disease, hypothyroidism, nutritional deficiencies (e.g. vitamin B12), encephalitis, medicinal poisoning, etc. 

Characteristics / Symptoms

  • Early stage: become forgetful especially related to events that happened moments ago; may require assistance on carrying out complex household work; become moody, anxious and depressed.
  • Middle stage: memory loss become more severe, especially in relation to recalling recent events, people’s names or places, as well as increasingly having communication problems. They may repeatedly ask the same questions, show delay in response, or may be unable to live and carry out daily activities independently.
  • Late stage: unable to recognize family members; mood and behavior changes including double incontinence, aggressiveness and agitation.

Be aware: Don’t try to diagnose dementia for yourself or someone else. If you are worried about yourself or someone close to you, consult a doctor and discuss your concerns. Dementia can only be diagnosed by a qualified and experienced health professional.