It is common for patients receiving a manipulation of the cervical spine (neck) to experience some minor adverse effects. This can range from increase in neck pain, stiffness, and soreness to dizziness, fainting and headache.
Most of the time, these symptoms are temporary and go away within 24 to 48 hours. Many people have the opposite result. Their neck pain, stiffness, and numbness and tingling are gone or greatly reduced after chiropractic treatment.
In a small number of patients, more serious effects can occur. Stroke, blood vessel tears, and other neurologic problems have been reported. These occurences are estimated to be low to very low. The exact number or percentage of patients who have adverse responses to cervical spine manipulation remains unknown. More study is needed in this area.