Dementia: Symptoms & Signs

Medically Reviewed on 9/10/2019

Dementia is a serious loss of intellectual functioning that is severe enough to interfere with a person's level of social or occupational functioning.

Signs and symptoms of dementia are varied and range from mild to severe. Associated symptoms include memory loss, mental decline, confusion in the evening hours, disorientation, an inability to speak or understand language, mental confusion, inability to recognize common things, irritability, personality changes, and restlessness. Other symptoms and signs can include lack of restraint, wandering and getting lost, anxiety, loneliness, mood swings, depression, hallucination, paranoia, jumbled speech, and sleep disorder.

Causes of dementia

There are many causes of dementia. The most common causes of dementia include Alzheimer disease and vascular dementia (caused by narrowing of the blood vessels to the brain).

Other dementia symptoms and signs

  • Anxiety
  • Confusion in the Evening Hours
  • Depression
  • Disorientation
  • Getting Lost
  • Hallucination
  • Inability to Recognize Common Things
  • Inability to Speak or Understand Language
  • Irritability
  • Jumbled Speech
  • Lack of Restraint
  • Loneliness
  • Memory Loss
  • Mental Confusion
  • Mental Decline
  • Mood Swings
  • Paranoia
  • Personality Changes
  • Restlessness
  • Sleep Disorder
  • Wandering


The abbreviated term ADHD denotes the condition commonly known as: See Answer

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Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.