TENS for Primary Dysmenorrhea

Primary dysmenorrhea is a common gynecological condition characterized by recurrent menstrual pain in the absence of identifiable pelvic pathology. It affects a substantial proportion of women of reproductive age and is frequently associated with symptoms such as abdominal cramps, low back pain, nausea, fatigue, and headache. The condition may negatively affect daily functioning, academic performance, and quality of life. Despite its high prevalence, many women continue to experience inadequate pain control or adverse effects from pharmacological treatments.

Menstrual pain in primary dysmenorrhea is primarily associated with increased production of prostaglandins in the endometrium during menstruation. Elevated prostaglandin levels increase uterine contractility and vasoconstriction, which can result in uterine ischemia and activation of nociceptive pathways. These mechanisms contribute to the characteristic cramping pain experienced during menstruation.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used as first-line pharmacological treatment because they inhibit prostaglandin synthesis. However, some women experience insufficient pain relief, contraindications, or adverse effects associated with pharmacological therapies. For this reason, there is growing interest in non-pharmacological approaches to the management of primary dysmenorrhea.

Transcutaneous electrical nerve stimulation (TENS) is a non-invasive electrotherapy modality widely used for pain management in various clinical conditions. TENS delivers low-voltage electrical currents through electrodes placed on the skin, stimulating peripheral nerves. The analgesic effect of TENS is thought to be mediated by several physiological mechanisms, including activation of large-diameter afferent fibers that inhibit nociceptive transmission at the spinal cord level (gate control mechanism), as well as activation of descending inhibitory pathways and endogenous opioid release.

Several studies have suggested that TENS may reduce pain intensity in women with primary dysmenorrhea. In addition, portable TENS devices allow self-administration of therapy and may represent a convenient and accessible strategy for managing menstrual pain outside of clinical settings.

The aim of this randomized controlled pilot study was to evaluate the effectiveness of a portable transcutaneous electrical nerve stimulation device in reducing pain intensity in women with primary dysmenorrhea.

Participants diagnosed with primary dysmenorrhea were recruited and randomly allocated to one of two groups: an intervention group receiving portable TENS therapy or a control group receiving usual care. Randomization was performed using a simple allocation procedure to assign participants to either group.

Participants in the intervention group used a portable TENS device applied to the lower abdominal region during menstrual pain episodes. The device delivered alternating stimulation cycles combining high-frequency stimulation (85 Hz) and burst stimulation (2 Hz). This combination of stimulation parameters was selected to potentially activate both segmental analgesic mechanisms and endogenous opioid-mediated pathways.

Each treatment session lasted approximately 20 minutes and was applied during menstrual pain episodes. Participants were instructed on the correct placement and use of the device before beginning the study.

Participants in the control group continued their usual management strategies for menstrual pain, which typically consisted of analgesic medication taken as needed.

The study was conducted over two to three menstrual cycles. During this period, participants recorded their pain intensity and medication use. Pain intensity was assessed using a visual analogue scale (VAS), which is a widely used and validated tool for measuring subjective pain intensity.

Additional outcomes were assessed to explore the potential broader effects of the intervention. Quality of life was evaluated using the Short Form-12 Health Survey (SF-12). Anxiety and depression were assessed using the Hospital Anxiety and Depression Scale (HADS). Female sexual function was evaluated using a validated questionnaire. Analgesic medication use was also recorded during the study period.

Data collected during the study were analyzed to compare pain intensity and other outcomes between the intervention and control groups across menstrual cycles. The results of this study are intended to contribute to the evidence regarding the effectiveness of portable TENS devices as a non-pharmacological intervention for primary dysmenorrhea.

The findings may help inform future research and support the development of non-invasive strategies to improve pain management and quality of life in women experiencing menstrual pain.

Inclusion criteria

• Women diagnosed with primary dysmenorrhea

History of recurrent menstrual pain without identifiable pelvic pathology

Regular menstrual cycles

Age between 18 and 45 years old

Pain intensity of at least 4 on a 10-cm Visual Analogue Scale (VAS)

Willingness to participate in the study and to comply with study procedures

Provision of written informed consent

Exclusion criteria

Secondary dysmenorrhea associated with identifiable pelvic pathology

Pregnancy

Irregular menstrual cycles

Use of hormonal contraceptives initiated or modified during the study period

Presence of gynecological or systemic conditions that could influence menstrual pain

Contraindications to transcutaneous electrical nerve stimulation (TENS), such as pacemaker implantation or skin lesions at the electrode placement site

Inability to understand study procedures or complete study questionnaires