Objective: To synthesize the evidence on the effectiveness, mechanisms, dosing, and safety of shortwave diathermy (SWD) in rheumatoid arthritis (RA), and to identify research gaps.
Methods: We conducted a narrative review of clinical trials, practice guidelines, and mechanistic studies involving SWD or thermotherapy in RA, prioritizing high-quality publications from 2000–2025. Where RA-specific data were limited, we selectively considered studies in osteoarthritis and chronic musculoskeletal pain.
Results: RA-specific evidence for SWD is scarce, with most studies being small and heterogeneous in treatment parameters. A Cochrane review found no convincing benefit of thermotherapy, including diathermy, on pain, function, or joint damage in RA. Current EULAR and ACR guidelines focus on disease-modifying antirheumatic drugs (DMARDs) and do not issue specific recommendations for SWD, but allow adjunctive rehabilitation modalities once disease activity is controlled. Data from osteoarthritis suggest that thermal SWD may provide small-to-moderate short-term improvements in pain and function, whereas athermal pulsed regimens show inconsistent results. Common treatment parameters include 27.12 MHz, 10–30 minutes per session, 3–5 sessions per week for 2–4 weeks.
Conclusion: SWD is not a substitute for DMARD-based control of RA, but may be considered as an adjunct to relieve pain and stiffness in patients with stable disease activity after contraindications are excluded. Large, well-designed randomized trials in RA, with standardized dosing and systematic reporting of adverse events, are still needed.