The common cold and salt therapy
The common cold is one of our most frequent illnesses: an adult catches it an average of 2–3 times a year, while a child may have it 5–6 times. More than 200 different viruses can cause it – most often rhinoviruses – so there is no “medicine” for it: antibiotics have no effect on viruses, while pharmacy products only ease the symptoms.
In this article, I’ll explain what you should know about the common cold (and when it may be more than a cold), how salt works in a congested nose, what the research actually says – including its honest limitations – and I’ll show you step by step how to do it at home: from the recipe for homemade saline to the technique of irrigation and gargling. There is also a separate chapter on the other, long-term side of salt treatment: inhaling salty air – from salt rooms to home salt nebulisers.
Key point
The key to salt treatment for the common cold is TIMING and REGULARITY: in the Scottish study, treatment began within 48 hours of the first symptoms and was repeated several times a day – resulting in an illness that was 1.9 days shorter, 36% less use of pharmacy medicines and 35% less spread within families.1 The mechanism is more than simple irrigation: according to the researchers, cells produce an antiviral substance (hypochlorous acid) from the chloride in salt – so salt supports the body’s own defence.7 Salt treatment also has a long-term side: regular inhalation of salty air (halotherapy) was studied in children who often became ill and led to fewer respiratory infections – the preventive effect was still detectable at the 12-month follow-up.9
The basics of the common cold – and when is it more than a cold?
The common cold is a viral infection of the upper respiratory tract: the lining of the nose and throat becomes inflamed, followed by a runny or blocked nose, sneezing, a scratchy throat, and sometimes a slight fever and tiredness. It typically lasts 7–10 days: the first 2–3 days are the worst, followed by gradual improvement. Two practical truths: antibiotics do not work against viruses (taking them only causes harm), and a cold usually runs its course – the immune system overcomes it, while our role is to provide support: rest, fluids and symptom relief.
| Sign | What might it mean? | What to do |
|---|---|---|
| Symptoms ease within 7–10 days | Usual viral cold | Home care: rest, fluids, saline nasal care |
| Symptoms lasting beyond 10 days or worsening AGAIN after temporary improvement | Possible bacterial superinfection or sinusitis | See a doctor – details in the sinusitis article |
| High fever (above 38.5 °C), severe headache, facial pain, earache | Possible complication (sinusitis or middle-ear infection) | See a doctor – use a lower threshold for children |
| Difficulty breathing, wheezing, bloody discharge | Lower respiratory involvement or another cause | See a doctor as soon as possible |
How does salt work in a congested nose?
The first effect of saline irrigation is tangible: the fluid physically washes virus-filled mucus, attached pathogens and inflammatory substances out of the nasal passages – leaving fewer viruses to continue infecting the mucous membrane. A solution that is saltier (more concentrated) than body fluids also draws water out of the swollen mucous membrane – just as a cucumber covered with salt releases liquid – so the nose “deflates” and breathing becomes easier, without medicated nasal drops, which should generally be used for no more than 5–7 days.
The thinner, more mobile mucus is then moved out more effectively by the cilia – the airways’ self-cleaning conveyor belt.8 That is why nasal breathing feels easier for hours after irrigation.
The most intriguing scientific aspect of salt treatment comes from a research group in Edinburgh: in a laboratory study, they showed that mucous membrane cells produce hypochlorous acid – the body’s own “household disinfectant” – from the chloride ion in salt, thereby reducing viral replication.7 Salt therefore does not “kill” the virus directly. It gives the cells ammunition for their innate defences.
This explains one of the most interesting findings in the Scottish study: the amount of virus in the noses of people rinsing with salt water fell much faster from day to day1 – so the participants not only recovered sooner, but were also less infectious: transmission within families fell by 35%.
The most frequently cited study was conducted by Scottish (Edinburgh) doctors with 66 adults: those who started concentrated saline nasal irrigation and gargling within the first 48 hours of symptoms recovered almost 2 days earlier on average, used one third less pharmacy medicine and passed the cold on to family members one third less often – 93% of participants felt that the method had helped them.1 For the sake of honesty: this was a small pilot study, so the researchers themselves called for stronger confirmation. That follow-up has now been completed: in 407 children, saline nose drops shortened the cold by 2 days (6 days compared with 8 days in the group receiving usual care), and transmission within families also became less frequent.2
The broader picture is more cautious, but points in the same direction: according to a strict international review that analysed the studies on the subject together, saline nasal treatment “probably alleviates” some cold symptoms – in the largest paediatric study there was less runny and blocked nose, and fewer nasal drops were used – but the studies were small and of mixed quality.3 Pooled analyses of research involving children reached the same conclusion: nasal symptoms improve, less medication – including antibiotics – is needed, and the method is safe.45
How to do it at home – step by step
| Step | How? |
|---|---|
| 1. Preparing the solution | 1 litre of distilled, sterile or boiled for at least 5 minutes and cooled to body temperature water + 25–30 g (2–3 tablespoons) of additive-free salt = 2.5–3% concentrated saline solution |
| 2. Nasal irrigation | Lean over a sink, tilt your head to the side and pour or squeeze the solution into the upper nostril (using a nasal rinse pot or syringe); let it flow out of the other nostril, then change sides. At the end, blow your nose GENTLY |
| 3. Gargling | Gargle with the same solution for 30–60 seconds, in 2–3 rounds – the study also treated the throat because the virus multiplies there too1 |
| 4. Frequency | 4–6 times a day during the first days of the illness (at least 3–4 times); reduce the frequency as you improve |
| 5. Timing | Start at the FIRST symptoms (scratchy throat, sneezing), preferably within 48 hours – this is when the studies started treatment and is one of the secrets of its effect12 |
| 6. For children | For small children, saline nose drops or nasal spray is the practical option (the large paediatric study also used drops2); use a smaller volume and gentle technique |
The water rule is sacred here too
NEVER use untreated tap water for water introduced into the nose – use only distilled, sterile or boiled-and-cooled water. Rare pathogens that may occur in tap water (including the amoeba Naegleria fowleri) can cause a serious infection when entering through the nose. Tap water is safe to drink – but not for nasal irrigation. Wash and dry the irrigation device after every use.
My advice
For a cold, salt treatment is like firefighting: it is most useful at the first spark. That is why the winning strategy is preparation: keep additive-free salt, a nasal rinse pot and a tried-and-tested recipe at home – and at the first scratchy throat, start the 4–6-times-a-day routine that same day, with irrigation and gargling together. The second front is the night: a salt aerosol device humidifies and cleans the nasal mucous membrane during sleep, when you cannot irrigate – instead of tossing and turning with a blocked nose, this is the most noticeable difference for many people. And do not forget the cold’s two ancient allies: rest and plenty of fluids – salt comes alongside these, not instead of them.
Inhaling salty air – the long-term salt therapy for colds
Nasal irrigation is the “rapid response” treatment for a cold – but salt also has another, older application: inhaling salty air, known technically as halotherapy. The idea comes from salt mines, where respiratory complaints were noticeably rare among miners. Two forms developed: dry salt aerosol (salt rooms, where a halogenerator disperses salt particles into the air) and moist salty vapour, nebulised from saline – used in spa inhalation rooms for more than a hundred years, and also the principle behind home ultrasonic salt nebulisers. The common point is particle size: salt particles invisible to the naked eye and much smaller than a human hair (0.5–5 thousandths of a millimetre) settle on the nasal and pharyngeal mucosa and also reach deeper parts of the airways – where the cold virus is active.
Nebulised saline inhalation has a significant medical tradition and institutional background in Hungary. The patient information from the Department of Otorhinolaryngology and Head and Neck Surgery at Semmelweis University describes the inhalation room at St Gellért Spa, which has operated since 1918: patients inhale for 15–20 minutes salty vapour made up of half-thousandth-of-a-millimetre droplets nebulised from saline. According to the clinic’s description, salt deposited on the mucous membrane dilutes thickened secretions and restores the mucosa’s self-cleaning function, allowing pathogens and impurities to leave the airways more quickly – recommended uses include catarrhal conditions, chronic sinusitis and allergic rhinitis. The information sheet also cites research data from 2012: regular inhalation of salty vapour reduced upper respiratory illnesses in children.14
This 2012 finding can also be traced in the scientific literature: in the clinical study, children who often became ill received a course of halotherapy, and the researchers described measurable anti-inflammatory and secretion-clearing effects. Most interestingly, the preventive effect remained at the 1-, 3-, 5- and 12-month follow-ups – respiratory infections were still less frequent months after the course.9
The remaining pieces of the picture point in the same direction: in acute rhinosinusitis in children, halotherapy as part of combined treatment improved nasal mucosal function and ciliary activity10; the “foundational study” of halotherapy, published as early as 1995, described the mucus-thinning and airway-clearing effect of salt aerosol11; and a 2022 review concluded, based on 13 studies, that halotherapy may improve respiratory function and quality of life, with very few side effects – although there is still no official guideline, so the authors position it as a complementary treatment.12 In people with allergic rhinitis and chronic respiratory disease, a small Romanian institutional study measured improvement in inflammatory parameters after a course in a salt room.13
How do the two salt methods share the work during weeks with a cold? Like this:
| Situation | Irrigation + gargling | Ultrasonic salt nebuliser |
|---|---|---|
| Acute cold, during the day | The main tool: 4–6 targeted, concentrated sessions per day1 | Supportive treatment: the mucous membrane remains in a salty environment during the hours between irrigations |
| At night | Not practical | The main role is here: it continuously humidifies and cleans the blocked nose during sleep |
| Small child who cannot tolerate irrigation | Saline nose drops remain an option2 | Works during sleep – without the child’s cooperation |
| Prevention during cold and flu season | Evening irrigation as a routine | Regular use at night – supported by the long-term research findings914 |
What can a home ultrasonic salt nebuliser do?
A home device (such as SaltDome) nebulises saline into droplets small enough to inhale – but not in 15–20-minute treatment sessions. It works throughout the night, at a low intensity that does not disturb sleep. For a cold, it may add something in three ways: at night, it continuously moistens and cleans the mucous membrane of a blocked nose when you cannot irrigate; for a small child, it works during sleep when irrigation several times a day is not practical; and during cold and flu season, it supports a preventive routine based on the long-term research on salty air.914 No cold study has yet been conducted specifically with this type of device – the expected effect can be inferred from salt aerosol research and spa practice. The right expectation is not a cure, but a night-time and preventive approach used alongside irrigation.
What you need for salt therapy at home
SaltDome salt therapy device
Ultrasonic salt generator for use at night during sleep – it brings the principle of halotherapy into the bedroom: during the cold season, it supports a blocked nose at night; outside the cold season, it provides a long-term, preventive salt-based approach for every member of the family. For several rooms, the Duo and Family sets offer a solution.
Natural, additive-free rock salt
Parajdi or Himalayan rock salt without additives – ideal both for the salt generator and for the irrigation solution (instead of iodised table salt containing additives).
When NOT to irrigate – and when to see a doctor?
- Active nosebleed – stop irrigation until the bleeding has settled
- Earache or pressure in the ear – if middle-ear involvement is suspected, see a doctor first; forced irrigation may worsen the situation through the Eustachian tube
- Severe deviated nasal septum or recent nasal surgery – irrigate only with medical approval
- Symptoms lasting beyond 10 days or worsening again, high fever or facial pain – this is no longer a matter for home care: medical examination is needed
- Untreated tap water – never use it: use only distilled, sterile or boiled-and-cooled water
Frequently asked questions
For colds, the studies used a concentrated solution (saltier than body fluids): about 2.5–3% – that is 25–30 g (2–3 tablespoons) of salt per 1 litre of water.1 If this stings your nose, start with a weaker solution (9 g, or 1 level tablespoon per litre) and switch to the concentrated solution once you are used to it. For children, a milder, weaker solution and the drops or spray format are the established approach.2 Accurate measuring matters: the homemade version of “some salt in some water” is either ineffective or irritating.
According to the two most important studies, both: with salt treatment, the illness was almost 2 days shorter in adults and 2 days shorter in children.12 The honest context is that the adult study was a small pilot study, while the strictest international review uses cautious wording (“probably alleviates symptoms”, with mixed study quality).3 All sources agree on one point: the method is safe and inexpensive, with at most mild stinging as a side effect – in other words, the possible benefit-to-risk ratio is particularly favourable.
It depends on age: for infants and small children, use saline nose drops or a gentle nasal spray (the study of 407 children used drops safely in children under 62); older children can be taught gentle irrigation with a small volume. In the Czech schoolchildren’s study, regular saline nasal care not only helped with symptoms, but also had a PREVENTIVE effect: cold episodes recurred less often in the saline group and there were fewer complications.6 Reviews of studies in children found that less additional medication – including antibiotics – was used with the method.45
The Czech study provides some guidance: among 390 children, regular saline nasal care continued for several weeks after the cold season was associated with fewer returning cold symptoms and fewer sinusitis complications.6 The preventive effect in adults has been studied less, but the logic is the same: a clean, well-hydrated nasal mucous membrane is a better viral barrier. A reasonable routine during cold and flu season is evening saline nasal care (irrigation or aerosol), especially after crowded days or travel.
Start at the first symptoms, preferably within 48 hours – this is when treatment began in the studies, and salt can restrain viral replication most effectively at the beginning of the illness.1 Continue 4–6 times a day during the illness, then reduce the frequency as you improve, until the symptoms have gone. If symptoms last beyond 10 days, or worsen after temporary improvement, this is a medical matter – irrigation does not replace an examination.
The principle is the same: both put tiny, inhalable salt particles into the air – in a salt room, a halogenerator disperses dry salt, while a home device (such as SaltDome) uses ultrasound to nebulise saline. The latter is related to the principle of the salt inhalation rooms at spas, as described in the patient information from the clinic at Semmelweis University.14 The practical difference is in the dosing: a salt room means 30–40-minute treatment sessions, with travel and admission costs, while a home device works every night during sleep, without interruption. Most studies have been conducted in salt rooms912 – the advantage of the home format is consistency: for cold prevention, the method that helps most is the one you actually keep doing over the long term.
What the research says – answers to readers’ questions
“Have researchers really studied whether saline irrigation shortens a cold?”17
Yes, and the research was carried out by doctors from the University of Edinburgh. Of 66 adults with a cold, one half started nasal irrigation and gargling with concentrated saline several times a day within the first 48 hours of symptoms, while the other half treated their cold as usual. Those who rinsed recovered almost 2 days earlier, bought 36% less pharmacy medicine, infected their family members 35% less often, and cleared the virus from their noses faster.1 The explanation was also found in the laboratory: mucous membrane cells make an antiviral substance from the chloride in salt.7 An important limitation is that this was a small pilot study – which is precisely why the larger follow-up with 407 children was carried out.
“What has been proven in children?”2456
A Scottish study presented at a major international respiratory conference in 2024 included 407 children under six: in the group given concentrated saline nose drops, the cold lasted 6 days compared with 8 days in the usual-care group, and transmission within families also became less frequent.2 (The result has so far been presented at a conference; the detailed scientific paper is still being prepared, so the data should be considered preliminary.) The other paediatric studies say the same: according to a pooled analysis, saline nasal treatment eases nasal symptoms and reduces the use of other medicines, including antibiotics4, while a 2024 review specifically recommends it for symptom management.5 The Czech prevention study also described fewer recurrent colds.6
“Why are some scientists more cautious in their wording?”3
Because that is their job. In 2015, an international research network that produces the world’s strictest medical analyses compared data from five studies involving 749 patients. Its conclusion was that saline nasal treatment “probably alleviates” some cold symptoms – in the largest paediatric study there was less runny and blocked nose, and fewer nose drops were used – but the studies were small and of mixed quality, so we cannot yet speak of complete certainty.3 The lesson is twofold: on the one hand, salt treatment is not a miracle method and its effect is modest to moderate; on the other, it is inexpensive, safe and free from significant side effects – with this level of risk, “probably helps” is more than enough reason to make it part of the basic routine during a cold. The newer Scottish studies have also moved the field precisely in the requested direction – towards larger and more thorough research.12
“What about salt rooms? Are they just wellness, or is there research behind them?”91214
There is research behind them – a moderate amount, but real research. The strongest data in relation to colds comes from the 2012 paediatric study: in children who often became ill, a course of salt-room halotherapy had anti-inflammatory and secretion-clearing effects, and the preventive effect remained at the 1-, 3-, 5- and 12-month follow-ups.9 Based on 13 studies, the 2022 review described improvements in respiratory function and quality of life, with few side effects – but it stressed that there is still no official guideline and that halotherapy is a complementary treatment.12 In Hungary, the Department of Otorhinolaryngology at Semmelweis University also uses inhaled nebulised saline and, citing the 2012 paediatric data, describes it in its patient information as useful for reducing upper respiratory illnesses.14 The lesson is that inhaling salty air is not a competitor to irrigation, but the other shift – irrigation is the tool for acute days, while salt aerosol is the long-term, preventive approach.
Summary
What is this article about? A guide to salt treatment for the common cold: how a cold runs its course and its warning signs, the three effects of salt (washing, reducing swelling and supporting the cells’ antiviral defences), the research findings in plain language, precise steps for use at home from preparing the solution to gargling – and the long-term side of salt treatment: inhaling salty air (halotherapy), from salt rooms to home salt nebulisers.
Who is it for? Anyone who would like to make the days with a cold shorter and easier to tolerate – with particular attention to families with small children, where colds occur 6–10 times a year.
Main message: In the studies, nasal irrigation and gargling with concentrated saline, started early (within 48 hours) and repeated several times a day, shortened colds by almost 2 days, reduced medicine use and reduced transmission within families – in children, saline nose drops produced the same result. The long-term approach is inhaling salty air: according to salt-room research, it reduced respiratory infections for months in children who often became ill – a principle brought home by a salt nebuliser. The method is inexpensive and safe; its two firm rules are to use treated water and to seek medical advice when symptoms last beyond 10 days or worsen.
Next step: Prepare your “cold kit” (additive-free salt, a nasal rinse pot and the recipe), and at the first symptoms start the 4–6-times-a-day irrigation-and-gargling routine – at night, switch on the salt generator in the bedroom.
Read more
Scientific sources
- Ramalingam S, Graham C, Dove J, Morrice L, Sheikh A. (2019). A pilot, open labelled, randomised controlled trial of hypertonic saline nasal irrigation and gargling for the common cold. Scientific Reports. DOI: 10.1038/s41598-018-37703-3
- Ramalingam S, et al. (2024). Hypertonic saline nose drops as a treatment in children with the common cold (ELVIS-Kids trial) – conference presentation. European Respiratory Society Congress, Vienna. ERS abstract
- King D, Mitchell B, Williams CP, Spurling GKP. (2015). Saline nasal irrigation for acute upper respiratory tract infections. Cochrane Database of Systematic Reviews. DOI: 10.1002/14651858.CD006821.pub3
- Cabaillot A, Vorilhon P, Roca M, et al. (2020). Saline nasal irrigation for acute upper respiratory tract infections in infants and children: a systematic review and meta-analysis. Paediatric Respiratory Reviews. DOI: 10.1016/j.prrv.2019.11.003
- Cruz M, Roteia C, Marques Ferreira A, et al. (2024). Nasal irrigation with saline solution for pediatric acute upper respiratory infections: a systematic review. Cureus. DOI: 10.7759/cureus.75464
- Šlapak I, Skoupá J, Strnad P, Horník P. (2008). Efficacy of isotonic nasal wash (seawater) in the treatment and prevention of rhinitis in children. Archives of Otolaryngology – Head & Neck Surgery. PubMed: 18209140
- Ramalingam S, Cai B, Wong J, et al. (2018). Antiviral innate immune response in non-myeloid cells is augmented by chloride ions via an increase in intracellular hypochlorous acid levels. Scientific Reports. PubMed: 30206371
- Wasik AA, Tuuminen T. (2021). Salt therapy as a complementary method for the treatment of respiratory tract diseases, with a focus on mold-related illness. Alternative Therapies in Health and Medicine. PubMed: 34726628
- Khan MA, Chervinskaia AV, Mikitchenko NA. (2012). The use of halotherapy for the health improvement in children at institutions of general education. Voprosy Kurortologii, Fizioterapii i Lechebnoi Fizicheskoi Kultury. PubMed: 22908472
- Khan MA, Khoruzhenko OV, Vakhova EL, et al. (2015). The role of non-medicamental technologies in the rehabilitation of the children presenting with acute rhinosinusitis. Voprosy Kurortologii, Fizioterapii i Lechebnoi Fizicheskoi Kultury. DOI: 10.17116/kurort2015436-40
- Chervinskaya AV, Zilber NA. (1995). Halotherapy for treatment of respiratory diseases. Journal of Aerosol Medicine. DOI: 10.1089/jam.1995.8.221
- Barber D, Malyshev Y, Oluyadi F, et al. (2022). Halotherapy for chronic respiratory disorders: from the cave to the clinical. Alternative Therapies in Health and Medicine. PubMed: 32827399
- Lazarescu H, Simionca I, Hoteteu M, et al. (2014). Surveys on therapeutic effects of "halotherapy chamber with artificial salt-mine environment" on patients with certain chronic allergenic respiratory pathologies and infectious-inflammatory pathologies. Journal of Medicine and Life. PubMed: 25870681
- Department of Otorhinolaryngology and Head and Neck Surgery, Semmelweis University. Effects of salt therapy – patient information (institutional source). semmelweis.hu. semmelweis.hu
