"...health web sites share your search queries with 3rd parties..."
For anyone looking for health information (in English), I recommend the NHS website. (Start your search from there rather than Google if you're worried about being tracked). It may not be the best-looking website, but the info is written by medical professionals and there are no commercial interests since the NHS is funded by the UK taxpayer.
They have an A-Z of conditions, a symptom checker, videos and much more. (I presume this is all available to anyone outside the UK)