Balneotherapy for pain in fibromyalgia: is there evidence to support subsidized therapy in Portugal? An evidence-based review

Abstract

Fibromyalgia (FM) is a chronic condition characterized by widespread pain, fatigue, mood, and sleep disturbances, predominantly affecting women. Treatment includes pharmacological and non-pharmacological approaches, such as balneotherapy (BT). This review evaluated the evidence on the effectiveness of BT in managing FM-related pain and its potential inclusion for reimbursement by the Portuguese National Health Service. We systematically searched clinical guidelines, systematic reviews, meta-analyses, and randomized controlled trials (2004–2024). The inclusion criteria followed the PICO model: adults with FM, BT, or hydrotherapy interventions, comparison with education or other therapies, and outcomes related to pain improvement. Of 234 articles identified, nine met the criteria. The European League Against Rheumatism (EULAR) recommends BT as an adjunctive treatment, and meta-analyses and clinical trials consistently demonstrate its effectiveness. BT was associated with significant pain reduction (standardized mean difference −0.8 to −1.8) with benefits lasting 3–6 months and only mild, transient adverse events. These findings suggest that BT is a safe and clinically effective adjunctive intervention for pain management in fibromyalgia, supporting consideration for inclusion among reimbursed indications in Portugal (strength of recommendation A).