Are neck adjustments safe?

All health treatments have the potential for adverse effects. On very rare occasions, neck adjustment has been associated with stroke and stroke-like symptoms. However, a scientific study published in February 2008 looked at data from Ontario hospitals over a nine-year period covering over 100 million person-years. The authors of this study found no evidence of excess risk of stroke associated with chiropractic care compared to medical doctors care (“primary care”). The most reasonable explanation in both instances may be related to timing. Early symptoms of a stroke in progress can be neck and/or head pain, which may lead the patient to seek care from their chiropractor or doctor for this pain before the condition is diagnosed. 

Reference to scientific study:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2271108/