Head-out immersion in natural thermal mineral water for the management of hypertension: a review of randomized controlled trials.

Hypertension is a major public health problem in the world, and the management of hypertension has always been a research of interest. Balneotherapy, with its recreational aspect, is more acceptable than medication intake and lifestyle change for the management of hypertension. The aim of this review was to summarize the current available data on the clinical effects of head-out immersion in natural thermal mineral water (HINTMW) as the most common method of balneotherapy used in the management of hypertension. We screened the PubMed, EMBASE, Cochrane Library, China Science and Technology Journal, China National Knowledge Infrastructure, WANFANG, and China Biology Medicine disc databases and selected 12 randomized controlled trials involving a total of 1122 participants. Among 12 trials, HINTMW was taken as the only intervention in only one study, HINTMW was taken in addition to basic antihypertensive drugs in three studies, and HINTMW was taken in combination with advice to follow nonpharmacological methods in one study involving participants who partly used antihypertensive drugs, while HINTMW combined with other interventions, such as natural convalescent factor therapy, psychotherapy, exercises, nutrition therapy, and integrated care, was taken in addition to basic antihypertensive drugs in the other 7 studies. Our results showed that natural thermal mineral water immersion alone or natural thermal mineral water immersion as an adjuvant therapy to medication or natural thermal mineral water immersion combined with other interventions had no adverse effects on hypertensive patients, and most even had positive effects. However, more high-quality evidences on therapeutic effectiveness of natural thermal mineral water immersion on hypertension are needed from additional randomized controlled trials with high methodological quality.