The effects of conventional, warm and cold acupressure on the pain perceptions and beta-endorphin plasma levels of primiparous women in labor: A randomized controlled trial

•This study uses endorphin theory to explain how acupressure relieves pain.•This study found that conventional, warm and cold acupressure reduced its participants’ labor pain.•Conventional, warm and cold acupressure increased its participants’ β-endorphin plasma levels.•Conventional, warm and cold acupressure can be used to relieve labor pain. This study was performed to determine the impact of different acupressure procedures, performed on women's hands during labor, on β-endorphin plasma levels and labor pain perception. Randomized controlled experimental trial This study was conducted with 140 pregnant women in the delivery rooms of a university research and training hospital and a state hospital in a province in the Black Sea Region of Turkey. This study was conducted with three experimental groups (who had conventional, warm and cold acupressure on their LI4 acupressure point) and one control group (no acupressure). Each group included 35 pregnant women. The data were collected using a personal information form, the Labor Intervention Follow-up Form, the Visual Analog Scale (VAS) and the Verbal Category Scale (VCS). Its main outcomes were the women's labor pain perceptions and β-endorphin plasma levels. The experimental and control groups had homogeneous introductory characteristics. The experimental groups had significantly higher mean VAS and VCS posttest scores than the control group (p