Salt Caves and Salt Air: What Halotherapy Can Do for Your Airways and Skin

Maybe someone gave you a voucher for a salt cave. Maybe you have been coughing since your last infection, or your child always seems to have a runny nose. Maybe you are simply looking for a place where nobody needs you for an hour.

Behind all of this is an understandable need. You want to breathe more freely. And you want to know whether salt plays a part in that.

To answer this, I look through several lenses: studies on salt chambers and caves, studies on inhaling saline solution, data from the Dead Sea and KPNI. KPNI stands for Clinical Psychoneuroimmunology, the interplay of nerves, the immune system, hormones and metabolism.

What happens to the air in a salt cave?

The walls look like those of a mine. There is hardly any smell, and yet you feel as if you are breathing in something special. What exactly is floating in the air?

Halotherapy, speleotherapy, salt cave: three terms

Speleotherapy means cave therapy. People spend time in natural caves or former mines. A Cochrane team describes it as common in parts of Central and Eastern Europe, but almost unknown in the United Kingdom and the United States.

Halotherapy takes its name from the Greek word for salt. Here, the microclimate of a salt mine is recreated in a room above ground. The salt cave in your city is usually such a room, with salt on the walls and floor.

How much salt reaches your airways?

Now it gets concrete. In a Finnish study, the salt concentration in the active chambers was 6.6 and 10.8 milligrams per cubic meter, and 0.3 in the placebo room. At rest, you breathe about 6 to 8 liters of air per minute.

In 45 minutes, that adds up to roughly a third of a cubic meter of air. Even at the higher concentration from this study, you would inhale only about 3 milligrams of salt. And only part of that stays in your airways.

For comparison: in a large study on inhalation in cystic fibrosis, each dose put 4 milliliters of a 7 percent solution into the nebulizer. That contains 280 milligrams of salt, roughly a hundred times as much.

Real mine, artificial cave

A natural salt mine is something different from a room with salt on the walls. In the historic Bochnia salt mine in Poland, the temperature fell from 20.8 to 15.5 degrees Celsius between the entrance and the depths of the mountain. At the same time, humidity rose from 55.9 to 77 percent.

Researchers from AGH University of Krakow measured the total particulate matter in this mine air at 21 to 79 micrograms per cubic meter. Among the water-soluble components, sodium chloride dominated. That is far less than the milligram amounts in chambers with a halogenerator. Air measurement

The measurement methods are not identical, but the order of magnitude shows that a mine and a chamber are two different worlds. Natural caves can be even cooler and more humid. In a Czech therapy cave, temperature and humidity were constant at around 8 degrees Celsius and 95 percent.

And now you know why the taste of salt on your lips does not yet tell you how much salt has reached your airways.

Can a salt cave help with asthma?

You know the whistling sound when you breathe out. The tightness when the air is cold or the pollen is flying. And the wish to depend less on your inhaler.

What the best studies show

Oversensitive airways are like a smoke detector that goes off as soon as you make toast. The airways contract in response to small triggers, such as cold air, fragrances or exertion. This oversensitivity, known as bronchial hyperresponsiveness, is exactly what the two best studies on salt chambers measured.

The same group wanted to know whether an effect on inflammation lay behind this. In a second double-blind study of 39 adults, the salt chamber did not change the eosinophilic inflammatory cells in sputum, neither at 6.6 nor at 10.8 milligrams of salt per cubic meter.

Older studies come mainly from caves and tunnels. In 2001, a Cochrane team led by Beamon found only three controlled studies on speleotherapy for asthma, with a total of 124 children. Only one of them was of acceptable methodological quality. Two studies reported better lung values in the short term, yet a reliable conclusion about effectiveness was not possible.

When salt irritates the airways

Here is a point that is often overlooked. For the airways, salt is not a neutral substance. Hypertonic saline, meaning a strongly salty solution, is one of the so-called indirect challenge tests in lung function diagnostics.

According to a technical standard of the European Respiratory Society (ERS), such tests cause the airways to narrow via the body's own signaling pathways that are involved in asthma. This is precisely why they are suitable for detecting asthma.

A Romanian review of halotherapy for asthma shows how close these two uses lie together. Of 18 original papers included, ten dealt with saline as a challenge test in diagnostics. Only four examined a treatment.

The amount of salt in a salt cave is likely to be considerably smaller than in such a test. With very sensitive airways, however, even a small trigger can cause coughing or tightness. So listen to your body and not to the session schedule.

In allergology, halotherapy is viewed with reservation. A review by Agnihotri and Greenberger lists it among the unproven treatment methods for allergic and immunological diseases.

If you have asthma and would like to try a salt cave, talk to your doctor first. Take your rescue inhaler with you, sit near the door and go outside as soon as coughing or tightness begins. And never change your maintenance therapy because of a salt treatment.

And now you know why the same substance appears as a treatment in one study and as a test for sensitive airways in another.

Salt caves for COPD, bronchiectasis and long COVID: What do studies show?

With COPD, every staircase becomes a negotiation. The morning cough, the sticky mucus, the worry about the next infection. An hour in a lounge chair that is supposed to make breathing easier sounds tempting.

During my research, I did not come across a separate Cochrane review specifically on salt chambers in COPD. There are hints from animal models: a Chinese research group saw fewer signs of inflammation in the lungs of rats with a COPD model under halotherapy. According to the author information, one co-author works for a technology company, and results in rats cannot simply be transferred to humans. Animal study

Caves and tunnels: the newest larger study

Two further studies from German-speaking countries add to the picture. A group from Witten/Herdecke University repeatedly measured the gas exchange capacity of the lungs in 46 people with post-COVID syndrome, on days with and without speleotherapy. They found no change, not even in people who had more sessions.

A Salzburg group led by Freidl compared a ten-day program of winter sports and speleotherapy with winter sports without the tunnel in adults with allergies or asthma. Quality of life and allergy symptoms improved in both groups. The researchers found no effect on an inflammatory marker in exhaled air in either group.

With COPD or bronchiectasis, the foundation remains what has been well studied: your inhaled medications, exercise, respiratory physiotherapy and protection against infections. A salt cave can be a pleasant break if your condition is stable and your doctor agrees. You can read how you can influence your nervous system through your breathing in Breathing techniques and the vagus nerve.

And now you know why a good experience in a tunnel and an effect on the lungs can be two different things.

Salt cave or inhaling saline solution: What is the difference?

Maybe there is a nebulizer in your cupboard. Saline in, mouthpiece to your lips, ten minutes of fine mist. Isn't that the same as a salt cave, just less cozy?

How salt can get mucus moving

Imagine the lining of your airways as a conveyor belt. Tiny cilia push a thin layer of mucus toward your throat, along with dust and germs. For the belt to keep running, the fluid layer beneath it needs enough water.

Salt attracts water, just as salt draws water out of cucumber slices. When concentrated salt reaches the airway lining, water flows into the fluid layer. The mucus can become more fluid, and this often triggers coughing as well, which can help to clear it.

A review by Elkins and Bye describes exactly this mechanism in cystic fibrosis. The hypertonic solution osmotically replenishes the dehydrated fluid layer, improves the flow properties of the mucus and stimulates coughing. After a single dose, the effect lasts only briefly, and with regular inhalation it lasts longer.

A team led by Robinson in Sydney made this visible in 1996. In twelve people with cystic fibrosis, the airways cleared 26.5 percent of a labeled aerosol within one hour after 7 percent saline, compared with 14.7 percent after normal saline.

Even here, though, things are not quite that simple. In the ISIS trial with 321 children with cystic fibrosis under the age of six, the 7 percent solution did not reduce the number of exacerbations. A 2023 Cochrane review rated the evidence for lung function as very uncertain. It classified 15 of 24 studies as being at risk of bias, because participants could tell the solutions apart by their taste.

Bronchiectasis and bronchiolitis: mixed results

In bronchiectasis, meaning permanently widened airways with a lot of mucus, the picture is mixed. In an Australian study of 40 people, quality of life and lung function improved equally over one year with 6 percent saline and with normal saline. Bacterial colonization of the sputum also decreased in both groups.

This is an intriguing hint that even isotonic inhalation, meaning saline with the body's own salt concentration, might have an effect. Without a group that did not inhale at all, however, this cannot be said with certainty.

In 2026, a meta-analysis from the same research group summarized the mucoactive agents used in bronchiectasis. It found no significant reduction in exacerbations and only a small gain in lung function, with very low certainty of evidence.

In the British trial, participants were tested before the start to see whether their airways tolerated the hypertonic solution. Such a supervised test is recommended because the airways can narrow. Twelve of 145 people tested did not pass it on the first attempt. Seventeen later stopped inhaling because of tolerability problems, even though they had passed the test.

In infants with acute bronchiolitis, a mostly viral inflammation of the smallest airways, hypertonic saline is used in some hospitals. A Cochrane review of 34 studies with 5,205 infants found a hospital stay that was on average 0.4 days shorter, with low certainty of evidence. Reported side effects included increased coughing, restlessness and bronchospasm, usually mild and subsiding on their own.

If you are thinking about inhaling because of sticky mucus, have it clarified which solution suits you. Isotonic saline corresponds to the salt content of the body and served as the comparison in many studies. In asthma, bronchiectasis or cystic fibrosis, hypertonic solution should only be used after talking to your doctor and with a first dose under supervision. Keep your nebulizer clean according to the manufacturer's instructions.

And now you know why the word salt can mean very different things for a lounge chair and for a medically dosed inhalation.

Salt caves for children: What applies to runny noses, tonsils and asthma?

Winter has barely begun, and your child is coughing again. Their nose has been running for weeks, and at night they snore. You would like to do something gentle that doesn't require any more medication.

You already know the pilot study from Haifa with children with mild asthma: less sensitive airways, but no better lung function. For children with frequent respiratory infections, I found no controlled study on salt caves with a convincing methodology.

For a runny nose: salt water in the nose

If your concern is runny noses and infections, nasal irrigation is the more obvious route. The salt water lands exactly where the cold sits, in an amount you decide yourself.

In 2015, a Cochrane review by King and colleagues found only five randomized trials with 544 children and 205 adults. Most results showed no difference. A larger study in children found small benefits for secretions and nasal congestion, though their clinical significance could be small. As a side effect, a few people experienced mild discomfort or a burning sensation in the nose.

In adults, a Scottish pilot study found that rinsing the nose and gargling with a homemade hypertonic salt solution shortened a cold by 1.9 days on average. A larger study from Pakistan, by contrast, found no benefit in COVID-19 when the rinses started up to five days after symptoms began.

For children with asthma, frequent bronchitis or shortness of breath, the plan belongs in the hands of your pediatrician before you visit a salt cave together. Infants with breathing problems always need a medical assessment. You can read how time outdoors and contact with nature might shape a child's immune system in Contact with nature in children.

And now you know why, for a child's nose, simple salt water is closer to the data than a lounge chair in the salt.

Going to a salt cave with a cold? When you should be careful during cold and flu season

Your throat feels scratchy, your nose is blocked. The salt cave appointment was booked ages ago, and you think: right now, the salt might do me good.

One room, many breaths

In a salt cave, several people often lie in the same, usually closed room for 45 minutes. A review in the journal Science summarizes that respiratory viruses do not only spread via larger droplets. Fine aerosols floating in the room air also play an important role.

How much this matters in a salt cave depends on ventilation, room size and occupancy. To my knowledge, it has not been specifically studied there. But the logic is the same as in any waiting room.

Salt air is not germ-free

The early description of halotherapy spoke of a low-germ, allergen-free environment. Measurements paint a more nuanced picture. In the air of the Bochnia salt mine, a Polish research group found bacteria, fungi and salt-loving archaea, a separate group of microbes. Air analysis

Deep inside the mountain, salt-loving microbes dominated. Yet at the very spot used for halotherapy, bacteria that do not need salt predominated. The study leaves open why this is so.

In a Czech therapy cave, no living nontuberculous mycobacteria could be cultured from the air. The researchers rated the risk as low, but recommended monitoring the air in such facilities regularly.

You can read when exercise makes sense again after a cold in Exercising with a cold. You can find out what studies show on herbal cold remedies in Echinacea, elderberry and pelargonium.

And now you know why, during cold and flu season, the best salt cave is sometimes your own sofa.

Salt and skin: What about atopic dermatitis, psoriasis and the Dead Sea?

Your skin feels tight, it itches, it cracks on your fingers. On your last vacation by the sea it was suddenly calmer, and ever since you have been wondering whether it was the salt.

What makes the Dead Sea special

The Dead Sea lies lower than any other place on land. Its water is among the saltiest on Earth, and magnesium salts dominate among its minerals.

A group from Ben-Gurion University has been measuring UV radiation there for more than 25 years. From these data, schedules were developed for when and for how long people with psoriasis should go out into the sun, depending on the month and the time of day.

An older Israeli analysis compared UVB doses. The mean dose of a four-week Dead Sea climatotherapy was among the lowest described for psoriasis to subside. It was reported that after four weeks the lesions had largely receded in more than 80 percent of those treated.

In atopic dermatitis, an Israeli group led by Adler-Cohen followed 49 adults through climatotherapy with sea bathing and gradually increased sun exposure. The SCORAD severity score fell by 39 points on average, and skin-related quality of life also improved markedly. Here, too, there was no comparison group.

A systematic review by Katz and colleagues concluded that the evidence is solid mainly for psoriasis, supported by the special solar radiation and by bathing in the salt water. It found no increased occurrence of skin cancer, but it did find signs of more sun-related skin damage.

Salt bath plus light: the Regensburg studies

In atopic dermatitis, another Regensburg study of 180 people showed a similar pattern. The combination of salt bath and light performed 26.2 percent better than light alone, and mild side effects occurred somewhat more often with the combination.

Even without light, magnesium-rich salt water might do something for the skin. A group in Kiel led by Proksch had people with dry, atopic skin bathe one forearm in a 5 percent Dead Sea salt solution for six weeks and the other in tap water. On the salt side, the skin was more hydrated, smoother and less red, and where the barrier was impaired, it improved as well. The salt used came from a Swiss manufacturer.

And the salt cave? On the skin, there are only a few papers on it, mostly in Russian, whose abstracts provide hardly any robust figures. The difference from the Dead Sea is large: there, the skin lies in very salty water and under dosed sunlight, whereas in a salt cave only a trace of salt floats in the air.

If you have psoriasis or atopic dermatitis, it is worth talking to your dermatologist about light therapy, including in combination with salt baths. UV light is medicine with side effects and belongs in expert hands. You can read how to handle the sun wisely in everyday life in How much sun does the body need. You can find out what is behind the idea of detoxing through the skin in Detoxing through the skin.

And now you know why your skin experiences something different at the Dead Sea than in the salt cave around the corner.

Sea climate, thalassotherapy and heliotherapy: What makes the coast different

You are standing on the beach, the wind tastes of salt, the waves are rolling in. After a few days, you breathe more deeply, sleep better, and your skin feels calmer.

Thalassotherapy refers to applications using seawater and the sea climate, heliotherapy to the targeted use of sunlight. On the coast, the two come together, along with wind, exercise and a different daily routine.

In 2011, Schuh and Nowak from LMU Munich assessed climatotherapy for the Deutsche Medizinische Wochenschrift. For atopic dermatitis and asthma at moderate altitudes, they saw evidence of short-term and longer-term effects. On the North Sea and the Baltic Sea, by contrast, the effects remained uncertain, especially for the classic areas of application. For the Dead Sea, they described longer-lasting improvements.

What else counts on the coast is hard to measure: wide open space, the rhythm of the waves, water for swimming, light on your skin. I describe what the mountains can do for breathing, blood and metabolism in Mountain air and altitude.

If you go to the sea, make full use of it: go outside every day, move along the water, dose the sun and get enough sleep. With skin diseases or asthma, medically supervised climatotherapy can be an option to discuss with your doctors. You can read why exercise in green spaces and by the water may be especially good for you in Green exercise: moving outdoors.

And now you know why the sea has more to offer than the salt cave that imitates it.

Relaxation, breathing, mucous membranes: What a salt cave can plausibly do

Perhaps a thought crossed your mind while reading: So my hour in the salt cave was pointless? No. It was just perhaps something other than what it said on the flyer.

Four lenses on an hour in the salt

Through the KPNI lens, a session in a salt cave touches all four major control systems of your body. Not equally strongly everywhere, and not equally well documented everywhere.

A meta-analysis by Buxton and colleagues evaluated 18 studies on nature sounds. On average, it found less stress and annoyance as well as better scores for health and mood. The natural sounds associated with such benefits included the sounds of wind and water.

An Italian online survey questioned people who had used a patented salt chamber system in 80 centers. After ten sessions, more than 92 percent said their health concern had eased. Particularly often, they mentioned better sleep and more relaxation.

Most had heard about the treatment by word of mouth, not through medical advice. A survey like this without a comparison group measures satisfaction, not effectiveness. But it does show what people look for there and find: calm.

If you are mainly looking for calm, you can also find it without salt: ten minutes of slow exhaling, a walk by the water, a well-ventilated, quiet corner at home. You can read more about this in Forest bathing, Fresh air and oxygen and Mouth taping and nasal breathing.

And now you know why the most valuable part of a salt cave might be the lounge chair.

Three levers if you would like to use a salt cave

You don't have to choose between enthusiasm and rejection. Three directions are enough to start with.

And now you know why a salt cave can do the most for you when you know what you can expect from it.

Frequently asked questions about salt caves

Where else this topic comes into play

Airways, skin and recovery are cross-cutting topics. These articles approach them from other directions.