Wikipedia
Halotherapy, derived from the Greek halos, meaning "salt", is a form of alternative medicine which makes use of salt. Numerous forms of halotherapy have been known of and used for millennia. One finds the first mentions of spa resorts in Poland in records dating from the twelfth century. They relate to bathing in mineral waters. Locations exist in the United States and Canada that attempt to reproduce the atmospheric salt concentrations found in Polish halotherapy spas.
Medical health experts have said that halotherapy is an unproven treatment that lacks scientific credibility. Methodological limitations call into question studies that showed improvement in symptoms of chronic obstructive pulmonary disease following halotherapy.
Inhalation of hypertonic saline can stimulate bronchoconstriction, which may be used in the diagnosis or evaluation of asthma symptoms.