Whether it's a tummy ache or a pain in the knee, Google is working to come up with better answers to questions on specific health issues.

Google says around one per cent of all internet searches are "symptom-related" but that health content online "can be difficult to navigate, and tends to lead people from mild symptoms to scary and unlikely conditions, which can cause unnecessary anxiety and stress."

On Monday, the search giant said it was upgrading its health results for its mobile application in English in collaboration with Harvard Medical School and the Mayo Clinic.

This will provide the most likely diagnoses in a box at the top of search results in a move aimed at helping users cut through the clutter, although it's not intended as a substitute for a doctor's opinion.

"When you ask Google about symptoms like 'headache on one side,' we'll show you a list of related conditions ('headache,' 'migraine,' 'tension headache,' 'cluster headache,' 'sinusitis," and 'common cold')," product manager Veronica Pinchin said in a blog post.

"For individual symptoms like 'headache,' we'll also give you an overview description along with information on self-treatment options and what might warrant a doctor's visit," the post said.

"By doing this, our goal is to help you to navigate and explore health conditions related to your symptoms, and quickly get to the point where you can do more in-depth research on the web or talk to a health professional."

Pinchin said symptom searches and other medical information on Google are "intended for informational purposes only, and you should always consult a doctor for medical advice."

Google said the new search would be rolling out on mobile in the United States in the coming days and that "over time, we hope to cover more symptoms, and we also want to extend this to other languages and internationally."