The relative risk of a chiropractic adjustment is very low compared to the related risks of many other medical procedures that people use everyday, and assume to be safe and without risk. Such a comparison is the relative risk of a basic over the counter pain tablet or pill such as NSAIDS.
Because just about every medical, chiropractic, or dental procedure have some associated risk, from time to time the media presents a "news" story concerning the dangers of such procedures including the chiropractic adjustment. Often, these "news" stories do not present a balanced or statistically factual side of the issue, and produce more "fear" and "alarm" than "news", appropriate warning, and measured concern. Stories of this nature can take an unfortunate event or outcome and portray it in such a way that makes it seem like it is a daily event, fact or eventual outcome.
A complete copy of published medical literature and comprehensive articles regarding the safety and relative risks of receiving chiropractic care can easily be found by visiting masschiro.org. These articles are found under the heading of chiropractic information, then click on research or articles.