Salt therapy, salt caves or halotherapy
Halotherapy, also known as salt therapy, is a spa-type therapy that claims to bring health benefits by surrounding a person with salt in real or simulated salt caves covered in Himalayan salt.
Salt therapy also takes the form of salt rooms and breathing through salt pipes, called speleotherapy.
Supporters of salt therapy say simply sitting in a space surrounded by salt creates a microclimate that may be beneficial for some respiratory and skin conditions. However, not much good quality research has been published about these claims.
The theory is that by being in a salt room, cave, or using a salt pipe, you breathe-in small salt particles which may help the symptoms of conditions like asthma.
However, although some adults and children with respiratory conditions try salt therapy privately, it is not included in NHS or British Thoracic Society asthma guidelines.
Asthma UK says there isn't any scientific evidence to show it may help the condition.
The Irish advertising regulator upheld a complaint against one salt therapy provider for failing to provide evidence to support health claims it was making about "drug-free, natural treatment that eases coughing, congestion, breathing difficulties, and other symptoms."
One review of research on salt therapy for COPD ( chronic obstructive pulmonary disease) involving more than 1,000 people concluded that: "Rcommendations for inclusion of halotherapy as a therapy for COPD cannot be made at this point and there is a need for high quality studies to determine the effectiveness of this therapy."
A study of people with bronchiectasis damage to their lungs, but who did not have cystic fibrosis, looked at whether mined salt and salt crystal inhalation could help the condition. Of those who took part, 65% said they were satisfied with halotherapy and asked to have it again. However, testing didn't find people's quality of life or lung function had been improved by the treatment.
Asthma UK stresses that anyone trying salt therapy should not use it to replace any standard medical treatment for respiratory problems.