New figures from the Alzheimer's Society show that, in some parts of the East Midlands, just four in ten people with dementia are being diagnosed with the condition.
The charity says it's disappointing that the number of cases being spotted varies so greatly between different parts of the region.
Our correspondent Peter Bearne has been talking to one woman who says health professionals repeatedly refused to accept her elderly mother had the disease.
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A sunny but chilly start. Cloud increasing with a little rain affecting northern and western areas, especially over the Derbyshire hills.
After a mainly dry, and locally chilly start, cloud will thicken, with some patchy rain possible across northern counties.
Becoming generally dry overnight with clear spells. A sunny but chilly start tomorrow. Cloud increasing with a little rain for some.