It is news that will have health obsessives breaking out in a sweat: browsing medical websites can be bad for you, a new study claimed today.
Researchers have spent 18-months studying a range of internet resources, which offer advice on the common symptoms and treatment of a variety of illnesses, from colds to cancer.
Doctors blame the wealth of web-based information for a rise in "cyberchondria" and claim scores of patients are heeding poor or mistaken advice.
They claim many patients make their own incorrect self-diagnosis after reading about conditions and then seek treatment they do not need.
Dr Neil Coulson, who led the research team at the University of Derby, said: "We found that people using these sites can take on board medical advice which is incorrect - an obvious concern.
"Indeed, the health profession has coined the phrase 'cyberchondria' for people using the internet for self diagnosis and presenting this misinformation to their GP."
The study examined sites dedicated to helping sufferers and carers of people with skin disorders, HIV and Aids, diabetes, cancer and Huntingdon's Disease.
It found that most sites connected to societies, charities or professional bodies offered sound advice, but that those set up by individuals could include glaring inaccuracies.
The team has urged health professionals to offer information and guidance to any website they discover which contains mistakes or untruths.
However, the team's report also praised the medium and claimed it helps people seek support from those suffering similar health problems.
"The internet is proving a great source of comfort that provides a vital support network to millions of people when used correctly," said Dr Coulson.
"Twenty or thirty years ago, a carer looking after a housebound relative may not have had ready access to such support.
"Now, without compromising the care of their relative, they can log onto the internet at whatever time of the day they like, seven days a week, and a support community is available made up of people in the same position, experiencing the same emotions."
PA