Experts outline 10 unusual early signs of dementia beyond memory loss

Experts outline ten unusual early warning signs of dementia that can appear years before memory loss, emphasizing that dementia is not solely a memory issue and that early diagnosis can guide treatment. In the United Kingdom, about 944,000 people live with dementia, with the United States home to roughly seven million living with the condition. University College London researchers project the UK figure could rise to about 1.7 million within two decades, a 40 percent increase from earlier forecasts.

Helen Metcalfe, a Dementia UK Admiral Nurse, told The Telegraph that the brain's complexity means each person's journey is different, and families often recognise signs only after diagnosis. "The brain is such a complex organ, and everybody's journey is completely different. It is often only after diagnosis that families look back and recognise there were a few signs that were not obvious at the time," she said. Professor Jonathan Schott, chief medical officer for Alzheimer's Research UK and a neurology professor at the Dementia Research Centre, University College London, notes that "there's more to cognition than memory" and that some people with dementia may show little memory loss but clear impairments in vision, behavior or other domains. "We think that the underlying brain changes that cause dementia happen many years before symptoms arise, and start slowly and subtly," he said.

Together, the experts described ten warning signs that can appear with or without memory loss. Among them are a changed sex drive, unusual behaviour, a lack of empathy, changes in eating habits, nightmares, hallucinations, eyesight problems, bumping into things, and changes in speech, in addition to memory loss. Some people with frontotemporal dementia may crave sweet foods, while others experience a deterioration in language, making it harder to understand words or find the right words.

Frontotemporal dementia (FTD) has several subtypes. One form, primary progressive aphasia (PPA), can stop people from understanding words or from using language effectively, an effect Schott described as losing one's own personal dictionary. Another subtype, the behavioural variant FTD (bvFTD), can amplify sexual drive and lead to disinhibited or socially inappropriate behavior, which can be shocking for loved ones. In parallel with these changes, experts say the link between dementia and vision issues is well documented and can precede memory problems in some cases, particularly with a rare form known as posterior cortical atrophy, characterized by progressive degeneration in the back of the brain and more common among people in their 50s and 60s.

Vision problems can also manifest as people bumping into objects or misjudging a step as they navigate familiar spaces, prompting clinicians to assess depth perception during evaluation. Metcalfe notes that if a patient reports falls, depth-perception issues should be considered to determine whether they may be related to a cognitive decline rather than a purely orthopedic issue. The final warning sign discussed by the experts was nightmares, with some dementia patients reporting more vivid dreams and increased movement during sleep as the disease progresses.

Lewy body dementia (LBD), which shares features with Parkinson's disease, can produce coordination difficulties and visual hallucinations. Schott emphasized that such hallucinations are typically small and non-threatening, yet they can be distressing for patients and families. Nightmares and vivid dreams, as well as changes in perception, may appear alongside other cognitive changes, underscoring the idea that dementia can affect multiple brain functions long before traditional memory complaints become dominant.

The emphasis on non-memory signs reflects a broader understanding that dementia is a spectrum of conditions with a range of early manifestations. Memory loss remains a hallmark for many patients, but researchers say it is not universal in the early stages, and other cognitive domains—such as perception, behavior, and language—can show trouble first. This perspective supports the push for routine, comprehensive assessments when subtle changes in daily functioning arise.

Early diagnosis, while not curative, enables people to pursue personalized treatment plans and to access supports that can slow progression and improve quality of life. Dementia UK Admiral Nurses play a key role in providing frontline guidance to people diagnosed with dementia and their families, with about 450 nurses across the United Kingdom offering direct care, education, and practical support. Health officials and researchers say the rise in dementia cases—driven in part by aging populations—highlights the need for continued investment in clinical care, caregiver support, and public awareness about the diverse signs of this condition.