A syndrome is a group of symptoms that characterize a disease or other abnormal condition when they occur together. Some syndromes have been around so long they are really established diseases, while others remain syndromes because a definitive cause hasn't been found. Some syndromes are controversial while others are well established and accepted by all medical professionals. Some medical conditions you'll find on this list aren't syndromes at all (such as celiac disease and Lyme disease), but are on this list because they would be otherwise hard to find.
Social Security has impairment listings that list the criteria for disability for just a few of the following conditions, such as Sjogren's and Down syndrome. For the other conditions below, Social Security will evaluate the applicant's symptoms and restrictions and assess how they limit the applicant's ability to work.