Burning Mouth Syndrome: What’s the cause?

Introduction

Burning mouth syndrome (BMS) is a complex, vexing condition in which a burning pain occurs that may involve your tongue, lips or widespread areas of your whole mouth, without any obvious reason.

The disorder has long been associated with a variety of other conditions — including menopause, psychological problems, nutritional deficiencies and disorders of the mouth, such as oral thrush and dry mouth (xerostomia). Some researchers have suggested dysfunctional or damaged nerves as a possible cause. But the exact cause of burning mouth syndrome is often difficult to pin down, and pain may continue for months or years.

Treatment of burning mouth syndrome is highly individualized and depends on your particular signs and symptoms and on the underlying cause or causes, if they can be identified. Most people with burning mouth syndrome can control their symptoms through tailored treatment plans.

Other names sometimes used for burning mouth syndrome include scalded mouth syndrome, burning tongue syndrome, burning lips syndrome, glossodynia and stomatodynia.

Signs and symptoms

Photographs showing burning mouth syndrome Click for images of burning mouth syndrome
The main symptom of burning mouth syndrome is a burning sensation involving your tongue, lips, gums, palate, throat or widespread areas of your whole mouth. People with the syndrome may describe the sensation in the affected areas as hot or scalded, as if they had been burned with a hot liquid.

Other symptoms may include:

• Dry mouth
• Sore mouth
• A tingling or numb sensation in your mouth or on the tip of your tongue
• A bitter or metallic taste

Some people with burning mouth syndrome don’t wake up with mouth pain, but find that the pain intensifies during the day and into the evening. Some have constant daily pain, while others feel pain on and off throughout the day and may even have periods in which they feel no pain at all.

Burning mouth syndrome affects women seven times as often as men. It generally occurs in middle-aged or older adults. But it may occur in younger people as well.

Causes

The possible causes of burning mouth syndrome are many and complex. Each of the following possible causes applies to only a small portion of all people who complain of a burning mouth. Many people have multiple causes.

Identifying all of the causes is important so that your doctor can develop a treatment plan tailored for you. Possible causes include:

• Dry mouth (xerostomia). This condition can be related to use of certain medications, including tricyclic antidepressants, central nervous system depressants, lithium, diuretics and medications used to treat high blood pressure. It can also occur with aging or Sjogren’s syndrome, an autoimmune disease that causes both dry mouth and dry eyes.
• Other oral conditions. Oral yeast infection (thrush) is a common cause of a burning mouth that may also occur with other causes, such as diabetes, denture use and certain medications. Geographic tongue, a condition that causes a dry mouth and a sore, patchy tongue, also may be associated with burning mouth syndrome.
• Psychological factors. Emotional disorders, such as anxiety and depression, are often associated with burning mouth syndrome, as is an extreme fear of cancer. Although these problems can cause a burning mouth, they may also result from it.
• Nutritional deficiencies. Being deficient in nutrients, such as iron, zinc, folate (vitamin B-9), thiamin (vitamin B-1), riboflavin (vitamin B-2), pyridoxine (vitamin B-6) and cobalamin (vitamin B-12), may affect your oral tissues and cause a burning mouth. These deficiencies can also lead to vitamin deficiency anemia.
• Irritating dentures. Dentures may place stress on some of the muscles and tissues of your mouth. The materials used in dentures also may irritate the tissues in your mouth.
• Nerve disturbance or damage (neuropathy). Damage to nerves that control taste and pain in the tongue may also result in a burning mouth.
• Allergies. The mouth burning may be due to allergies or reactions to foods, food flavorings, other food additives, fragrances, dyes or other substances.
• Reflux of stomach acid (gastroesophageal reflux disease). The sour- or bitter-tasting fluid that enters your mouth from your upper gastrointestinal tract may cause irritation and pain.
• Certain medications. Angiotensin-converting enzyme (ACE) inhibitors, used to treat high blood pressure, may cause side effects that include a burning mouth.
• Oral habits. These include often-unconscious activities such as tongue thrusting and teeth grinding (bruxism), which can irritate your mouth.
• Endocrine disorders. Your oral tissues may react to high blood sugar levels that occur with conditions such as diabetes and underactive thyroid (hypothyroidism).
• Hormonal imbalances, such as those associated with menopause. Burning mouth syndrome occurs most commonly among postmenopausal women, although it affects many other people as well. Changes in hormone levels may affect the composition of your saliva.
• Excessive irritation. Irritation of the oral tissues may result from excessive brushing of your tongue, overuse of mouthwashes or consuming too many acidic drinks.

Often, more than one cause is present. Despite careful evaluation, doctors are sometimes unable to find the cause of burning mouth symptoms.