Burning mouth syndrome is a chronic condition that causes a persistent burning sensation in the mouth, even though no visible damage or cause can be found. It affects roughly 2% of people and can last for months or even years, creating daily challenges for those who experience it.
Epidemiology
Burning mouth syndrome affects approximately 2% of the population, making it relatively uncommon but significant for those who experience it[4][14]. The condition shows a striking difference between men and women, with women being up to seven times more likely to receive a diagnosis than men[2][4]. This gender disparity becomes even more pronounced when looking at specific age groups and life stages.
The syndrome overwhelmingly affects people who have gone through menopause, particularly postmenopausal women over the age of 60[2][11]. Studies have shown that approximately 85 percent of study subjects with burning mouth syndrome have been women, although epidemiologic studies show a more equal distribution when examining the general population[6][15]. The peak age of onset typically occurs from three years before menopause to twelve years after menopause[21]. However, the condition can also affect men and women before or during the perimenopausal period, though this is less common[4].
Among women seeking treatment specifically for menopausal symptoms, the prevalence appears much higher, with burning mouth complaints reported in 10 to 40 percent of these patients[6][15]. This contrasts sharply with lower prevalence rates of 0.7 to 2.6 percent found in broader epidemiologic studies[6][15]. The difference may be related to how the condition is defined in various research studies and which populations are being examined.
Causes
Understanding what causes burning mouth syndrome remains one of the biggest challenges for researchers and doctors. The condition is generally divided into two categories: primary burning mouth syndrome and secondary burning mouth syndrome, each with different underlying mechanisms[2][3].
Primary burning mouth syndrome refers to cases where the burning sensation occurs without any identifiable underlying medical problem[2][11]. Experts believe this form is caused by damage to the nerves that control pain and taste in the mouth[2][3]. These nerves stop functioning normally and send pain signals to the brain even though there is no actual injury or harmful stimulus present. This is called neuropathic pain, which means pain resulting from nerve malfunction rather than tissue damage[4][14]. Recent studies have pointed to dysfunction of several cranial nerves associated with taste sensation as a possible cause[6][15]. The nerves responsible for feeling pain in the mouth become easily stimulated and excited, transmitting pain signals without an actual painful stimulus[4].
Secondary burning mouth syndrome occurs when the burning sensation results from another identifiable medical condition[2][11]. When the underlying condition is treated successfully, the burning sensation typically goes away. Several medical conditions can cause secondary burning mouth syndrome, including dry mouth, which may result from certain disorders like Sjögren’s syndrome or from medications and treatments[3][12].
Oral infections, particularly yeast infections like thrush (also called candida), can produce burning sensations in the mouth[2][11][20]. Acid reflux, where stomach acid flows back into the mouth, can also cause burning symptoms[2][3]. Nutritional deficiencies, such as low levels of vitamin B12, vitamin B6, iron, or zinc, have been linked to the condition[2][3][11]. Hormonal changes from conditions like diabetes or thyroid problems may contribute[3][12][20].
Allergies to dental products, dental materials (usually metals), or certain foods can trigger burning sensations[3][12][20]. Some people experience symptoms due to reactions to certain types of toothpastes or mouthwashes, or from poorly fitting dentures or allergies to denture materials[5][20]. Oral habits such as tooth grinding or jaw clenching can lead to burning mouth syndrome symptoms[3][12]. Approximately one-third of people with burning mouth syndrome have an oral habit that may contribute to their symptoms[3][12].
In more than half of patients with burning mouth syndrome, the onset of pain is spontaneous, with no identifiable precipitating factor[6][15]. About one-third of patients can relate the time of onset to a dental procedure, recent illness, or medication course, including antibiotic therapy[6][15]. Regardless of how the pain begins, once it starts, it often persists for many years[6][15].
Risk Factors
Several factors increase the likelihood of developing burning mouth syndrome. Being in postmenopause is one of the strongest risk factors, as lower estrogen levels cause decreased taste bud sensitivity[2][11]. This hormonal shift appears to play a significant role, though researchers still don’t fully understand why. Interestingly, hormone replacement therapy generally does not prove effective in managing burning mouth syndrome symptoms in postmenopausal women[4][14].
Gender is a significant risk factor, with women far more likely to experience the condition than men[2][11]. This disparity remains consistent across multiple studies and populations. Age also matters, with the condition being more common in middle-aged or older people, particularly those over 60[2][11][20].
Certain health conditions increase the risk of developing burning mouth syndrome. People with diabetes or Sjögren’s syndrome have a higher likelihood of experiencing symptoms[2][11]. Those with chronic anxiety or depression also face elevated risk[2][11]. Having a condition called geographic tongue, which creates irregular patches on the tongue surface, increases the chances of developing burning mouth syndrome[2][11].
Nutritional deficiencies serve as important risk factors. Lacking adequate iron, zinc, vitamin B6, or vitamin B12 makes burning mouth syndrome more likely[2][11]. Taking certain medications, particularly those prescribed for depression or high blood pressure, may also increase risk[2][11].
Contributing factors may include adverse life events such as job loss or the death of a family member or spouse[4][14]. Psychiatric disorders including anxiety, depression, and post-traumatic stress disorder have associations with the condition[4][14]. Temporomandibular joint (TMJ) problems, chronic fatigue syndrome, and fibromyalgia also appear more frequently in people with burning mouth syndrome[4][14].
An interesting aspect involves genetic ability to taste. People can be classified as nontasters (who don’t taste things very strongly), medium tasters (who taste things the way most people do), or supertasters (who taste things really strongly)[2][11]. Many people with burning mouth syndrome are supertasters who no longer taste things as strongly as they used to. Research shows that many people with the condition also grind their teeth, which can make the burning feeling worse[2][11].
Symptoms
The hallmark symptom of burning mouth syndrome is a burning or scalding sensation in the mouth that occurs without any visible physical changes[1][16]. People commonly describe the feeling as if they injured their mouth with a very hot drink or scalded their tongue with hot food[1][5][20]. Although parts of the mouth may feel like they are burning, they will not be hot to the touch, and no soreness or redness will be visible in the areas that hurt[5][20].
The burning sensation most commonly affects the tongue, particularly the anterior two-thirds, but can also impact the lips, gums, roof of the mouth (palate), inside of the cheeks, throat, or large areas of the whole mouth[1][6][15][16]. The burning often occurs in more than one oral site simultaneously[6][15]. The anterior hard palate and the mucosa of the lower lip are frequently involved locations[6][15]. Facial skin is typically not affected[6][15].
Along with the burning sensation, many people experience other symptoms. Mouth pain may feel like tingling, scalding, or burning[2][11]. Numbness in the mouth that comes and goes is common[2][11]. Taste changes occur frequently, with people reporting bitter or metallic tastes in their mouth[1][2][16]. Some experience complete loss of taste[1][16]. Altered taste is such a common feature that it’s considered one of the characteristic symptoms of the condition[2][11].
Many people with burning mouth syndrome experience a feeling of dry mouth with increased thirst, even though they may actually have enough saliva[1][2][11][16]. This sensation of dryness is called subjective xerostomia because it’s a feeling of dryness rather than an actual lack of saliva. Some patients report a “draining” or “crawling” sensation in the mouth[4][14]. Tingling or stinging sensations in the mouth are also reported[1][16].
The discomfort from burning mouth syndrome follows several different patterns throughout the day. For many people, pain is absent or mild during the night and upon waking, but then increases throughout the day, becoming worst by late afternoon and into early evening[1][4][6][14][15][16]. The mouth might feel fine when first waking up, but then start to burn later, with the burning feeling getting worse as the day goes on[2][11]. When going to sleep, the pain might fade, but then when waking up, it starts all over again[2][11].
Other people experience continuous symptoms throughout the day from the time they awaken[4][14]. Some feel constant pain every day[3][5][12][20]. A smaller group has intermittent symptoms with pain that comes and goes, including some symptom-free days[1][4][14][16]. This intermittent pattern is the least commonly observed presentation[4][14].
The severity of pain ranges from moderate to severe and can be similar in intensity to toothache pain[6][15]. The burning can become so intense that it causes people to feel depressed or anxious[2][11]. Pain often interferes with the ability to fall asleep[6][15]. Some patients report trouble going to sleep and staying asleep throughout the night[4][14]. Perhaps because of sleep disturbances, constant pain, or both, patients with oral burning pain often have mood changes, including irritability, anxiety, and depression[6][15].
Sometimes the burning feeling may be briefly relieved during eating or drinking[1][3][12][16]. For many people, the pain is reduced when eating or drinking[3][12]. However, consuming hot drinks can exacerbate the burning oral pain[21], while chewing sugar-free gum seems to alleviate some symptoms for certain people[21].
Patients also often report other symptoms beyond the mouth. These may include headache, fatigue, shoulder pain, back pain, irritable bowel syndrome, burning of the skin or genital area, panic attacks, palpitations, and ringing in the ears[4][14]. The duration of symptoms varies widely. Burning mouth syndrome may last for months or years[1][3][12][16]. In rare cases, symptoms may suddenly go away on their own or happen less often[1][16]. Spontaneous partial recovery within six to seven years after onset has been reported in up to two-thirds of patients[6][15].
Prevention
Because the exact cause of primary burning mouth syndrome remains unclear, specific prevention strategies are difficult to establish. However, addressing risk factors and maintaining overall oral and general health may help reduce the likelihood of developing the condition or minimize symptom severity.
Maintaining good oral hygiene is important for overall mouth health. Brushing teeth twice a day and flossing daily can help prevent infections and reduce inflammation that might contribute to mouth discomfort. Regular dental check-ups allow for early detection and treatment of oral problems that could lead to burning sensations.
Addressing nutritional deficiencies may help prevent secondary burning mouth syndrome. Ensuring adequate intake of vitamin B12, vitamin B6, iron, zinc, and folic acid through a balanced diet or supplements can support nerve health and oral tissue integrity. If dietary intake is insufficient, speaking with a healthcare provider about appropriate supplementation may be beneficial.
Managing underlying medical conditions is crucial. Keeping conditions like diabetes, thyroid problems, and Sjögren’s syndrome well-controlled may reduce the risk of developing burning mouth syndrome. If dry mouth is a problem due to medications, discussing alternatives with a doctor might help prevent mouth burning symptoms.
Avoiding irritants can protect sensitive oral tissues. Limiting consumption of spicy or acidic foods, carbonated beverages, and alcohol may help prevent irritation. Avoiding smoking and using tobacco products is important, as they can dry out the mouth and potentially worsen symptoms. Choosing gentle oral care products without harsh chemicals or potential allergens may also be helpful.
Managing stress and mental health appears particularly important given the strong connection between stress, anxiety, depression, and burning mouth syndrome. Practicing stress reduction techniques such as relaxation, meditation, yoga, or other therapeutic approaches may help reduce risk. For those experiencing significant life stressors or mood disorders, seeking appropriate mental health support could potentially lower the likelihood of developing burning mouth syndrome.
Addressing oral habits like tooth grinding or jaw clenching is important, as these behaviors are common in people with burning mouth syndrome and may make symptoms worse. Wearing a mouthguard at night or working with a dentist on strategies to reduce these habits may be beneficial.
Staying well-hydrated helps keep the mouth moist and may prevent the dry mouth sensations that can accompany or contribute to burning mouth syndrome. Drinking plenty of water throughout the day supports overall oral health.
Pathophysiology
The pathophysiology of burning mouth syndrome involves complex changes in how nerves function and how the body perceives pain and taste. Understanding these mechanisms helps explain why people experience burning sensations even when no visible damage is present in their mouth.
For primary burning mouth syndrome, researchers believe the underlying mechanism is neuropathic pain, which means the pain arises from abnormal nerve function rather than from actual tissue damage or inflammation[4][5][14][20]. The nerve fibers in the mouth function abnormally and transmit pain signals despite the fact that there is no painful stimulus present[4][14]. The nerves responsible for feeling pain become easily stimulated and excited, sending signals to the brain that are interpreted as burning or pain sensations[4][14].
The condition specifically involves damage to the nerves that control pain and taste in the mouth[2][3][11][12]. Recent studies have pointed to dysfunction of several cranial nerves associated with taste sensation as a possible cause[6][15]. When these taste-related nerves don’t work properly, it affects how the brain interprets signals from the mouth. Changes occur in the way the nerves send messages to the brain about taste and temperature[5][20]. When the brain doesn’t understand these messages properly, it can cause the feeling of pain or burning[5][20].
The nerve damage makes the mouth feel like it’s burning and changes how things taste[2][11]. This explains why people with burning mouth syndrome often experience both burning sensations and altered taste perception simultaneously. The nerves affecting the area of the tongue that controls taste and pain become damaged, leading to both symptoms occurring together[2][11].
Hormonal changes appear to play a role in the pathophysiology, particularly in postmenopausal women. Lower estrogen levels cause decreased taste bud sensitivity[2][11]. Many people with burning mouth syndrome are supertasters who no longer taste things as strongly as they used to[2][11]. This change in taste perception appears connected to the development of burning sensations, though the exact mechanism linking hormonal changes to nerve dysfunction remains unclear.
For secondary burning mouth syndrome, the pathophysiology depends on the underlying condition causing the symptoms. When dry mouth is present, reduced saliva production can lead to irritation of oral tissues and altered nerve function. In cases of nutritional deficiencies, lack of essential vitamins and minerals affects nerve health and function, potentially leading to neuropathic symptoms. When oral infections like thrush are present, inflammation and tissue irritation trigger pain signals. In cases of acid reflux, stomach acid irritates oral tissues and nerves, causing burning sensations.
The pathophysiology may be multifactorial, meaning multiple factors contribute to the development and persistence of symptoms. Stress and anxiety appear to influence nerve function and pain perception. Psychiatric conditions like anxiety, depression, and post-traumatic stress disorder are commonly associated with burning mouth syndrome, suggesting that psychological factors interact with neurological mechanisms to produce or worsen symptoms[4][14].
The burning sensation can be constant or increase throughout the day, which may relate to accumulating nerve irritation or changes in how the nervous system processes pain signals over the course of a day. The fact that symptoms often improve during eating or drinking suggests that sensory input from food and beverages may temporarily interrupt or override the abnormal pain signals being generated by malfunctioning nerves.
Sleep disturbances and constant pain create a cycle where symptoms worsen mood changes, which in turn may amplify pain perception[6][15]. This interaction between physical symptoms and emotional well-being demonstrates how burning mouth syndrome affects multiple body systems and highlights the complex nature of its pathophysiology.
