Between 50% and 80% of dementia sufferers are not being diagnosed in primary care, a report claims.
According to the World Alzheimer Report 2011 by the Alzheimer's Disease International, there is a false belief among primary care professionals that memory loss is a 'normal' part of ageing.
The report calls for earlier diagnosis and identification of dementia to improve the treatment, information and care given to sufferers.
Early diagnosis allows people more time to plan their lives after diagnosis, and to make important decisions about future treatment and care, argues the report.
"What is clear is that every country needs a national dementia strategy that promotes early diagnosis and a continuum of care thereafter," said Professor Martin Prince of the Institute of Psychiatry, King's College London, and the main author of the report.
"Primary care services, specialist diagnostic and treatment centres and community-based services all have a part to play, but to differing degrees depending upon resources."
The National Institute for Health and Clinical Excellence (NICE) released guidelines on dementia care in March 2011.
The health watchdog recommends that primary care staff should consider referring people who show signs of mild cognitive impairment (MCI) for assessment by memory assessment services.
The Department of Health yesterday (14 September) pledged to invest £10m in memory services in a bid to improve dementia services.
"While there is no cure for dementia, we know that early diagnosis and early intervention can help people take control of their condition and plan for the future," said Paul Burstow, Care Services Minister.
"With access to the right services and support, people with dementia can continue to live well for many years. Memory services have a really important role to play in this."