 Prof Hollins says better communication training is needed |
People with learning disabilities and their families are being asked for their experiences of the NHS treatment. Research by the Disability Rights Commission (DRC) suggests they are four times more likely to die from a treatable illness.
A study showed learning-disabled people were 58 times more likely than others to die before the age of 50, a report for BBC Radio Five Live said.
Better communication training is needed for NHS staff, one specialist said.
The term "learning disabled" covers the 1.5m people in the UK with an IQ of 70 or under, caused by genetic abnormalities or birth defects.
It includes conditions like Downs Syndrome, foetal alcohol syndrome, severe autism and brain damage through head injury, or oxygen deprivation.
Sheila Hollins, professor of Psychiatry of Learning Disability at St George's Hospital in south London, said she thought "institutionalised discrimination" was partly to blame for the high death rate.
"It's a lack of awareness about just how much ordinary services need to be adapted to make sure people with learning disabilities get equal access and equal care," she told the BBC.
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"Doctors and nurses need to be able to take more time [with learning-disabled people] and have taken time to learn how to communicate and listen."
She said better training was needed as many health workers were unaware they lacked the skills and "just don't really know where to begin".
Helen Atkinson, from Darlington, Durham, is among those with first-hand experience of the problem.
In 2001, her husband John, 36, died from massive organ failure after a heart condition, two weeks after he left Darlington Memorial Hospital.
Both had learning disabilities and Mrs Atkinson felt the hospital had not fully explained to her the seriousness of her husband's condition.
After an investigation, the hospital's final report found: "On discharge, the staff were unaware of how little Mrs Atkinson really understood and overestimated the couple's ability to judge their own situation outside the hospital."
Carers 'in awe'
The hospital pledged to provide "better training in learning for all clinicians" and apologised and paid compensation.
The County Durham and Darlington Acute Services NHS Trust says its approach is now "different and much better".
Campaigner Jean Wilson, whose daughter has learning disabilities, said her experience of the NHS had been mixed - some staff were excellent while others she could "cheerfully throttle".
She believes part of the problem is that some carers are "in awe" of the medical profession, while she will challenge decisions she believes are discriminatory.
Health inequalities
She said: "I take out my biro and say: 'And your name is young man? I believe that 's discrimination and I will be going straight to your chief executive'," she said.
The Department of Health has acknowledged more work is needed to reduce "health inequalities" for those with learning disabilities.
Health minister Stephen Ladyman has said it was also working with Mencap on ideas for improving the health of those with learning disabilities, including the need for doctors to proactively identify their health problems.
A guide had also been issued to primary care professionals to share best practice.