A new study has found that patients who search their symptoms online before arriving at an emergency department are better able to communicate with doctors.

Ever turned to Dr Google to work out what that pain is and whether it's going to kill you?

Search engines can sometimes give more questions than answers, but one Australian study has found they can actually help when it comes time to see a doctor.

More than a third of 400 adult patients surveyed at two Melbourne emergency departments - St Vincent's and Austin Health - said they searched their symptoms before coming to hospital.

Contrary to perceptions this could lead people to "flood" emergency departments with less serious health problems, study co-author Dr Anthony Cocco said the practice was generally helpful - as long as patients went to reputable sites.

"Researching allows patients to be able to clarify and sort out what they're feeling," he told AAP.

"Most notably, they were able to ask more informed questions of their doctors and communicate more effectively."

Chest, stomach and back pain as well as headaches were the most common symptoms searched.

Of the 139 people who looked up their symptoms before going to emergency, 86 did so more than 24 hours in advance.

Most people who looked up health issues used the top-ranked sights on Google and did not spurn or doubt their practitioner's advice because of what they found, Dr Cocco said.

"I think that would be very reassuring for doctors."

However, some patients (76 of those surveyed) agreed looking up symptoms made them worried or anxious.

"Obviously, anytime you're unwell you're a bit anxious. People coming into emergency are coming in on their worst day," Dr Cocco added.

"But certainly our research is not indicating that it's leading more people to come into emergency."

He suggested doctors acknowledge and be prepared to discuss online searches with emergency patients.

"A lot of doctors are probably unaware of how much this is happening ... I think we need to be openly communicating, saying to patients 'have you looked into this?'"