According to research appearing in the February, 2001 issue of the Journal of Manipulative and Physiologic Therapeutics, chiropractic adjustments to the cervical spine may be beneficial to patients with high blood pressure. A total of 110 patients participated in two studies with 70 patients demonstrating signs of upper cervical subluxation/joint dysfunction. Patients receiving upper cervical adjustments had a significant decrease in systolic blood pressure compared to the control group.

Another study (J Chiropr Med. 2013 Jun;12(2):55-9) looked at 24 African American patients who received 23 chiropractic adjustments. They were diagnosed with prehypertension (120-139/80-89) or hypertension stage 1 (140-159/90-99).

The mean values of 3 baseline blood pressure readings were compared with the mean values of blood pressure readings taken on visits 21, 22, and 23. For the entire sample, reductions for both systolic and diastolic blood pressures were not statistically significant (P > .07). When 4 patients having body mass index values that were considered as outliers were excluded, a statistically significant decrease in diastolic blood pressure was observed (P = .004). By group, a statistically significant reduction occurred in the hypertension stage 1 group for systolic and diastolic blood pressures.