Google announced yesterday that they are expanding the search queries for health or medical symptoms to show you related queries.
This way if you search for something too specific, such as headache on one side, Google may show you related searches to pick from such as “headache,” “migraine,” “tension headache,” “cluster headache,” “sinusitis,” and “common cold.”
Google added:
Google said this is rolling out on mobile over the next few days, in English in the U.S. to start and will expand from there.
Forum discussion at Google+.