Access to information online often leads patients to diagnose themselves, making the job of healthcare professionals more difficult, doctors say.
"People type in their symptoms into Google and the results cause them to go into a panic," said Dr Aamerah Shah, of the American Hospital Dubai. "Symptoms can lead to either a simple or very serious diagnosis. But for some reason they don't pick up the minor things, only the major or fatal ones."
Pre-appointment research is common among younger, tech-savvy patients, doctors said.
Nearly a quarter of Dr Shah's patients research before they visit her, with cancer a common concern.
"Patients read 'cancer' online and they start to worry," she said. "They want to be fully investigated and they want every kind of scan. Then you have to sit with the patient and convince them that they don't need certain procedures done."
Dr Ihab Ramadan, a specialist in internal medicine at Medcare Hospital, said research had its uses.
"I would like it if a diabetic patient went online and researched the kinds of food he should eat and how to monitor his blood-sugar levels."
Dr Shah said it was also important that patients know where to look for the information.
"It should be from a credible source - usually websites that are validated by a known medical body," she said.