Health ConditionsSnoring (also termed stertor, from the Latin stertere, "to snore") is an abnormal breath sound caused by partially obstructed, turbulent airflow and vibration of tissues in the upper respiratory tract — including the uvula, soft palate, and base of the tongue — which occurs during sleep. It usually happens during inhalations.
Snoring is defined as the sound produced by the vibration of the soft tissues in the upper airway during sleep, occurring in approximately 40% of males and 30% of females habitually. Habitual snoring is common, though prevalence varies widely; in population studies 44% of men and 28% of women have been reported to snore.
Clinicians distinguish between several categories based on severity and associated pathology:
Snoring is defined as a coarse, harsh sound caused by the vibration of soft tissue in the upper airways involving anatomical structures such as the soft palate, uvula, and tongue base. The upper airway has been mathematically modelled as a tube with an elastic or collapsible section; as this section narrows, resistance to the flow of air increases.
Snoring consists of audible sounds produced during sleep caused by vibrations of throat muscles; these muscles vibrate more readily when they are relaxed during sleep and when air velocity is high. In a non-snoring adult the negative pressure required to close the upper airway is less than −25 cm water; snoring adults have a much more pliable airway, with closure during sleep occurring at pressures ranging from −2 to −10 cm water.
The fact that snoring and obstructive apnea only occur during sleep means that effective neuromuscular functioning of the upper airway during sleep is vital for the maintenance of unimpeded breathing. Clinical studies in humans have obtained evidence demonstrating that upper airway neural receptors sense the negative pressure generated by inspiration and "trigger," with a certain delay, reflex muscle activation to sustain the airway that might otherwise collapse. Increased latency of the reflex muscle activation in sleep, together with reduced strength of the reflex, have important clinical consequences.
Snoring can be analysed and measured by methods including equivalent continuous sound level, power spectrum analysis, and linear prediction coding (LPC), which can define the cross-sectional area of the upper airways and identify three snoring patterns: nasal, oral, and oronasal.
Obstructive sleep apnea may be associated with myriad clinical consequences such as increased risk of systemic hypertension, coronary vascular disease, congestive heart failure, cerebrovascular disease, glucose intolerance, impotence, obesity, pulmonary hypertension, gastroesophageal reflux, and impaired concentration. Recent research supports an association between both sleep apnea as well as snoring with cardiovascular risk factors, measures of subclinical atherosclerosis, and cardiovascular diseases.
Patients with OSA experience repetitive episodes of hypoxia and reoxygenation during transient cessation of breathing that provoke systemic effects, and there may be increased levels of biomarkers linked to endocrine-metabolic and cardiovascular alterations. Epidemiological studies have identified OSA as an independent comorbid factor in cardiovascular and cerebrovascular diseases. Both OSA and metabolic syndrome may exert negative synergistic effects on the cardiovascular system through multiple mechanisms — including hypoxemia, sleep disruption, activation of the sympathetic nervous system, and inflammatory activation.
Previous epidemiological studies have reported significant associations between snoring and diabetes mellitus, incident hypertension, angina pectoris, and incident coronary heart disease and stroke.
A large meta-analysis (966,652 participants, 40 studies) found that the pooled odds ratios between snoring and metabolic syndrome and its components, including hypertension, hyperglycemia, low HDL, high triglycerides, and abdominal obesity, were significantly elevated. Snoring was found to be a risk factor for metabolic syndrome, and a dose–response relationship existed between the two.
Factors that predispose to snoring, such as obesity, also increase the risk of sleep apnea. Obstruction of the pharynx by hypertrophied adenoids (tonsils) or obesity can also cause excessive snoring. Excess adipose tissue deposits around the pharynx and neck narrow the available airway lumen, increasing the likelihood of tissue vibration during sleep.
In a survey of 2,187 subjects in the Tucson Epidemiologic Study of Obstructive Airways Disease, major independent risk factors for snoring were male gender, age between 40 and 64 years, obesity, and current cigarette smoking. Factors that are difficult to modify, such as sex, age, family history, ethnicity, and craniofacial morphology — some of which may be genetically influenced — have an effect on whether one snores.
Modifiable factors such as obesity, alcohol consumption, smoking, and nasal symptoms are risk factors for snoring. In previous studies, current smokers had a higher risk (odds ratio 2.29) of snoring compared to non-smokers, and snoring was more prevalent in smokers and ex-smokers compared to never-smokers. Snoring prevalence remained elevated in subjects who recently quit smoking, but declined in ex-smokers to the level of never-smokers within four years of smoking cessation.
Since snoring is frequent in smokers and a common symptom — even a preclinical form of OSA — it is reasonable to speculate that smoking is an independent risk factor for snoring. Current studies have observed a synergistic effect between smoking and OSA, both increasing the risk of cardiovascular disease through oxidative stress, endothelial dysfunction, and abnormal inflammatory response.
A systematic review and meta-analysis showed that consumption of any alcohol increases the risk of OSA by 25% (any compared with none, or high compared with low intake), independent of obesity. Snoring prevalence was slightly increased in subjects who regularly used alcohol or medications as aids to sleep.
The risk of snoring increased in patients with nasal symptoms (odds ratio 1.38) even after adjusting for age, sex, and BMI, and when having allergic rhinitis (odds ratio 2.34). Data from the Wisconsin Sleep Cohort demonstrate a strong association between nocturnal nasal congestion and habitual snoring, with an odds ratio of 3.0.
Snoring has been found to have a statistically significant correlation with smoking, alcohol consumption, hypothyroidism, hypertension, allergic rhinitis, and antidepressant medications.
Having a relative who snores increases the odds of snoring. Genetic correlation analysis and genome-wide association studies have shown that snoring is genetically correlated with BMI, heart disease, and minimum blood oxygen saturation (SpOâ‚‚), among other traits.
Menthol, found in peppermint, has been widely used in lozenges, nasal sprays, vapo-rubs, inhalers, and cough syrups as a treatment for rhinitis associated with acute upper respiratory tract infection and allergy. As a plant extract, it has been used in traditional medicine in Asia for the treatment of respiratory diseases for hundreds of years, and was introduced to Western medicine at the end of the 19th century.
Multiple controlled human studies have examined the physiological action of menthol on nasal airway patency. Menthol inhalation had no consistent effect on objective nasal resistance, but the majority of subjects reported an increased sensation of nasal airflow and a cooling effect of menthol. The results indicate that menthol stimulates cold receptors in the nasal mucosa to create an increased sensation of airflow; no evidence was found in support of any nasal decongestant action for menthol.
In a double-blind randomised trial using 11 mg menthol lozenges in subjects with common cold, nasal airway resistance showed a significant increase in both the menthol and placebo groups over the 2-hour experiment with no difference between the groups, while subjects in the menthol-treated group showed significant subjective improvement in nasal sensation of airflow 10 minutes after dosing. It was concluded that menthol has no effect on objective nasal airway resistance but causes a marked change in nasal sensation with a subjective sensation of nasal decongestion.
Across multiple studies, the consistent conclusion is that menthol has no effect on objective measures of airflow, but significantly increases the perception of nasal patency. L-menthol caused a highly significant enhancement of nasal sensation of airflow, but the isomers D-isomenthol and D-neomenthol had no effect on nasal sensation. These findings show that L-menthol has a specific pharmacological action on nasal sensory nerve endings which is not related to its peppermint smell.
Evidence strength: Multiple small to moderate-sized controlled human trials confirm that menthol/peppermint creates a subjective sense of easier nasal breathing via cold-receptor stimulation, but objective airway measurements consistently show no meaningful reduction in nasal resistance. No controlled clinical trials specifically on snoring reduction have been published for peppermint. The evidence for subjective symptom relief is moderate; evidence for actual snoring reduction is absent.
Honey has been used across numerous traditional medicine systems — including Ayurveda, traditional Chinese medicine, and folk medicine in Europe and the Middle East — for respiratory conditions including coughs, sore throats, and inflammation of the mucous membranes. It has historically been consumed in warm water or tea as a soothing pre-sleep preparation.
Honey has well-established anti-inflammatory properties due to its high level of phenolic compounds which can act as antioxidants; sleep apnea patients have also appreciated its throat-soothing benefits. However, no controlled clinical trials specifically examining honey's effect on snoring frequency or intensity could be identified in the peer-reviewed literature. Proposed mechanisms — such as coating the oropharyngeal mucosa, reducing local inflammation, and thereby diminishing tissue vibration — are biologically plausible but unconfirmed by direct human trials targeting snoring as a primary outcome. Evidence for honey's direct anti-snoring effect is therefore anecdotal and preliminary only.
Eucalyptus leaf and its essential oil have been used in traditional Australian Aboriginal medicine and widely adopted in European and North American folk medicine for respiratory congestion, sinusitis, and bronchitis, typically via steam inhalation, chest rubs, or lozenges. Its active constituent, 1,8-cineole (eucalyptol), has documented expectorant and mild anti-inflammatory activity in the respiratory mucosa.
No controlled clinical trials specifically on eucalyptus and snoring were identified. Clinical evidence exists for 1,8-cineole in mucociliary function and airway inflammation in conditions such as chronic obstructive pulmonary disease (COPD) and sinusitis, but the translation of these findings to snoring reduction has not been directly tested. Evidence for snoring specifically: absent from the peer-reviewed literature.
Several systematic reviews and meta-analyses have examined the relationship between vitamin D status and OSA severity, which is directly relevant to snoring in the pathological spectrum. In an updated meta-analysis of 29 eligible studies comprising 6,717 participants, the results revealed that the serum 25(OH)D level was significantly lower in OSA patients than in controls. There was a relative insufficiency in serum 25(OH)D levels among OSA patients compared to control patients, which was incrementally exacerbated with increasing severity of sleep apnea; however, it was unclear whether a low 25(OH)D was a risk factor for OSA or if OSA was a risk factor for low 25(OH)D, and the association may be confounded by BMI.
Recent research has consistently highlighted the high incidence of vitamin D deficiency among patients with OSA, which often occurs independently of geographical location, suggesting that factors beyond lack of sunlight exposure may be involved. This review also found that reduced vitamin D may be associated with more severe manifestations of OSA, and some studies have found improvements in sleep quality and a reduction in OSA severity with supplementation.
In a cross-sectional study, vitamin D deficiency was associated with approximately threefold higher odds of severe OSA (OR 2.75); in stratified analyses, vitamin D deficiency predicted OSA severity among participants aged ≥50 years and those with BMI ≥30 kg/m², but not in younger and non-obese adults. The study provides further evidence of an inverse association between vitamin D levels and OSA severity and underscores the importance of considering vitamin D status as a potential modifiable factor in the comprehensive management of OSA.
Evidence strength: Multiple meta-analyses confirm an inverse association between serum vitamin D and OSA/snoring severity, but causality has not been established and the relationship is likely confounded by obesity. Interventional (supplementation) trial evidence is limited and preliminary. This is an area of active investigation.
Magnesium is discussed in natural-health literature in the context of sleep quality and muscle tone. Magnesium has anti-inflammatory properties which may be therapeutic for people with sleep apnea; it can be found in foods such as avocados, seeds and nuts, bananas, and leafy greens such as kale, spinach, and collard greens. Magnesium's known roles in neuromuscular function, regulation of muscle contraction, and modulation of inflammatory pathways make it biologically plausible as a supportive nutrient. However, no controlled trials specifically linking magnesium supplementation to snoring reduction have been published in the peer-reviewed literature. Evidence specifically for snoring: preliminary and indirect only.
Omega-3 fatty acids (EPA and DHA) have been discussed primarily in the context of the cardiovascular comorbidities of OSA rather than airway mechanics. Their well-established anti-inflammatory properties are relevant given the role of upper airway inflammation in snoring, and the documented cardiovascular risk elevation in chronic snorers. However, no controlled trials specifically examining omega-3 supplementation and snoring have been identified in the literature. Evidence specifically for snoring: absent; use is discussed for comorbidity management.
Phytomedicine covers the application of different components of plants — including blossoms, leaves, stems, and roots — as well as aromatic essential oils and herbal extracts, via herbal teas, massage, or steam inhalation. Phytomedicine is incorporated in many traditional medicines, including Traditional Chinese Medicine (TCM) and Kampo Medicine, and herbal remedies have played an important role in treatment from ancient to modern times. However, few of these preparations have been specifically tested in randomised controlled trials targeting snoring as a primary outcome.
Obesity is a major risk factor for OSA. Short-term randomised controlled trials have reported reductions in OSA severity following weight loss. An American Thoracic Society clinical practice guideline found that comprehensive lifestyle interventions produced reduced snoring as measured by the Snore Outcomes Survey (mean difference 7.2 points), and that the decrease in apnea-hypopnea index correlated with the magnitude of weight loss.
The MIMOSA randomised controlled trial evaluated a Mediterranean diet-based weight-loss intervention for OSA management. The MIMOSA study was designed as a single-center, single-blind, parallel, randomised controlled clinical trial to evaluate the effectiveness of a weight-loss Mediterranean dietary/lifestyle intervention on managing OSA.
In the INTERAPNEA randomised clinical trial, participants were randomised to receive usual care (CPAP therapy) or an 8-week weight loss and lifestyle intervention involving nutritional behaviour change, aerobic exercise, sleep hygiene, and alcohol and tobacco cessation. The intervention group had a 51% reduction in AHI.
In episodes of sleep apnea the upper airway is obstructed by posterior positioning of the base of the tongue so as to totally occlude the airway. Sleeping on the side instead of the back can help reduce snoring, because sleeping on the back can cause the tongue to fall back and block the airway.
Common correlations with snoring include age, being overweight, nasal and sinus problems, alcohol intake, smoking, certain medications, and sleep position. Restricting alcohol intake, particularly in the hours before sleep, is consistently identified in the literature as a modifiable factor for reducing snoring severity.
Snoring prevalence remained elevated in subjects who recently quit smoking, but declined in ex-smokers to the level of never-smokers within four years of smoking cessation. This suggests that smoking cessation is a meaningful long-term dietary/lifestyle intervention for habitual snorers.
While not nutritional, oropharyngeal exercises are a natural, non-pharmacological intervention studied specifically for snoring. A systematic review demonstrated that myofunctional therapy reduced snoring in adults based on both subjective questionnaires and objective sleep studies. The efficacy of oropharyngeal exercises is based on the fact that sleep-related breathing disorders are caused by a "double hit" from increased resistive loading of the upper airway by mechanical factors such as obesity, and absent compensatory neuromuscular responses. Improving neuromuscular responsiveness of these upper airway muscles can compensate for anatomical causes and treat the majority of snorers.
A 2020 Cochrane review identified nine eligible RCTs of myofunctional therapy for OSA, analysing 347 participants, though it noted that compared to sham therapy, myofunctional therapy may have little to no effect in reduction of snoring frequency in OSA, underscoring the need for further high-quality trials distinguishing primary snoring from OSA-related snoring.
Using a humidifier, taking a steam shower, or using a saline nasal spray can help alleviate congestion and reduce snoring caused by allergies. Humidifiers add moisture to the air, which is beneficial because dry air can irritate the respiratory system; humidifiers can also help decrease congestion, open airways, and promote clearer breathing. These interventions have not been subjected to large controlled trials for snoring specifically, and current evidence is observational.
5-HTP is the direct precursor to serotonin, which is a key neuromodulator for maintaining upper airway muscle tone during sleep. Animal studies show that blocking serotonin activity can induce snoring and upper airway collapse, reversed when serotonin returns. A 2024 review in MDPI's IJMS confirmed the central role of the 5-HT signaling pathway in OSA/snoring pathophysiology, and a 2023 observational study found negative correlations between blood serotonin levels and obstructive apnea and oxygen desaturation scores.
L-Tryptophan was studied in a 1983 PubMed study (Schmidt HS, Physiologist) in 15 patients with sleep apnea (12 obstructive), showing significant improvement in obstructive sleep apnea at an average dose of 2500 mg at bedtime, but not central apnea. It is a serotonin precursor, and serotonin is critical for maintaining upper airway muscle tone during sleep. L-Tryptophan has also been included in patented snoring treatment compositions.
Lavender essential oil was one of the components in the Prichard 2004 double-blind study blend (140 adult snorers) in which 82% of bed partners reported reduced snoring with the essential oil spray versus 44% with placebo. Lavender promotes muscular relaxation and sleep quality through calming of the nervous system. A 2020 RCT comparing lavender and peppermint aromatherapy confirmed improved sleep quality in cardiac patients.
Sweet marjoram (Origanum majorana) essential oil was included in the Prichard 2004 double-blind snoring study blend and is widely cited as an anti-snoring essential oil. It has antispasmodic and muscle-relaxant properties that may reduce pharyngeal tissue vibration. Marjoram's expectorant action can also help clear sinus and nasal congestion contributing to snoring.
Melatonin has been studied in patients with obstructive sleep apnea (OSA), the primary disorder underlying most snoring. A 2024 randomized double-blind placebo-controlled trial found 10 mg melatonin improved sleep latency, reduced mid-night wakeups, and enhanced sleep quality in OSA patients. Melatonin secretion is significantly altered in approximately 25% of OSA patients. It has also been included in patented snoring treatment formulations alongside L-tryptophan.
A randomized placebo-controlled trial in 20 adults with obstructive sleep apnea found that 600 mg NAC given three times daily for 30 days significantly reduced AHI, apnea-related arousals, oxygen desaturation, daytime sleepiness, and snoring (relative snore time and number of snore episodes). NAC is an antioxidant that mitigates oxidative stress and sympathetic nervous system excitation from intermittent hypoxia.
Peppermint essential oil was a component of the blend tested in a 2004 double-blind controlled study (Prichard, Phytotherapy Research) of 140 adult snorers from a snoring clinic, in which 82% of bed partners reported reduced snoring with the essential oil spray versus 44% with placebo. Its active compound menthol acts as a decongestant and has anti-inflammatory properties on nasal passages and upper airways. Aromatherapy with peppermint has also been studied for improving sleep quality in cardiac patients (randomized controlled trial, 2020).
Thyme essential oil was one of the components in the Prichard 2004 double-blind study (140 adult snorers) where the essential oil blend spray reduced snoring in 82% of users' bed partners versus 44% in placebo. Thyme's active compound thymol has antispasmodic and respiratory-clearing properties. Thyme is traditionally used in folk medicine for respiratory conditions and has become popular specifically for snoring.
A clinical study found that a 500 mg intravenous dose of vitamin C improved endothelial dysfunction in OSA patients (Am J Respir Crit Care Med, 2006). A combination of vitamin C (100 mg) and vitamin E (400 IU) twice daily for 45 days reduced apneic episodes and improved sleep quality in 20 men with OSA on CPAP. Animal models confirm vitamin C reduces oxidative and carbonyl stress in OSA. A UK Biobank cohort study of 68,221 participants examined the association between dietary vitamin C and sleep apnea.
Vitamin E, in combination with vitamin C (100 mg C + 400 IU E, twice daily, 45 days), was shown in a controlled study of 20 men with OSA on CPAP to reduce apneic episode frequency, improve sleep quality, and reduce daytime sleepiness. Animal studies confirm vitamins C and E together reduce oxidative and carbonyl stress from intermittent hypoxia in OSA models. Reduced vitamin E levels have been measured in OSA patients compared to controls.
Chamomile has a long tradition of use for snoring and sleep disorders through its muscle-relaxing and sedating effects on the respiratory airways. Traditional herbal medicine across Europe prescribes chamomile tea before bed to soothe throat tissues and reduce inflammation. It appears in essential oil blends recommended for snoring, including alongside thyme and marjoram in traditional practice.
Garlic has been used traditionally to reduce snoring by clearing the respiratory tract and reducing mucus buildup in nasal passages. Traditional practice involves chewing garlic cloves or consuming garlic before bedtime. It has anti-inflammatory and decongestant properties that may reduce upper airway obstruction contributing to snoring.
Valerian root (Valeriana officinalis) has a traditional history of use for snoring through its sedative and antispasmodic effects on respiratory tract tissue and sleep quality improvement. Traditional folk medicine prescribes valerian for snoring combined with thyme or fenugreek. Valerian essential oil is included in commercial anti-snoring essential oil formulations alongside lavender and chamomile.
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