These websites offer information about a wide range of topics. The websites are reliable and usually edited and updated by physicians. These websites have been consistently helpful over many years.
The commercial sites have significant advertising. Theoretically, this could introduce bias, but these websites disclaim such influence. The non-profit websites have little or no commercial advertising but do promote their own services. The federal government websites offer excellent, unbiased information.
This service informs patients about medical conditions that could be associated with their symptoms. These tools are not very accurate in making the “right diagnosis”. Instead, they may help the patient decide if the symptoms warrant medical attention.