Scalloped Tongue: A Complete Guide to Causes, Symptoms, and Treatments

Have you ever noticed wavy, rippled indentations along the sides of your tongue? This condition, known as a scalloped tongue, is often harmless on its own. However, it can be your body's way of signaling an underlying health issue that needs attention.

Also called a crenated tongue, wavy tongue, or pie crust tongue, this feature occurs when your tongue presses up against your teeth, leaving imprints. While it's usually painless, understanding its potential causes is the first step toward addressing the root of the problem. This comprehensive guide synthesizes medical research and expert opinions to explain what your tongue might be telling you.

What is a Scalloped Tongue?

A scalloped tongue is identified by the wavy, grooved indentations along its lateral edges. The condition isn't a disease itself but is a clinical sign that results from pressure against the teeth. This pressure is most often due to tongue swelling, also known as macroglossia, but can also be caused by behavioral habits or anatomical issues.

A clear image showing the wavy indentations characteristic of a scalloped tongue.

While the appearance can be concerning, the indentations themselves are rarely painful. However, if the underlying cause involves inflammation, you might experience some tenderness, redness, or soreness.

What Causes a Scalloped Tongue?

The reasons for a scalloped tongue are diverse, ranging from systemic health conditions to mechanical habits. A healthcare professional can help you pinpoint the specific cause.

Systemic and Medical Conditions

Several internal health issues can cause the tongue to swell, leading to scalloping.

• Sleep Apnea: Research increasingly points to a strong link between a scalloped tongue and obstructive sleep apnea (OSA). During sleep, individuals with OSA may subconsciously thrust their tongue forward against their teeth to open a restricted airway. One 2025 study found that a scalloped tongue can be a useful tool to detect severe sleep apnea [1].
• Hypothyroidism: An underactive thyroid gland can lead to a slowed metabolism and fluid retention, causing tissues throughout the body, including the tongue, to swell [2].
• Nutritional Deficiencies: A lack of essential nutrients, particularly B vitamins (B12, niacin, riboflavin) and iron, can cause tongue inflammation (glossitis) and swelling [3].
• Dehydration: When your body lacks sufficient fluids, it may try to conserve water, leading to tissue swelling, which can affect the tongue.
• Autoimmune and Infiltrative Diseases: Conditions like amyloidosis (a buildup of abnormal proteins), Sjögren's syndrome, and sarcoidosis can cause chronic inflammation and enlargement of the tongue [4].
• High Blood Pressure: A recent study in the American Journal of Hypertension noted a connection between scalloped tongues and higher blood pressure, suggesting it may be linked to inflammation and fluid retention [5].
• Congenital Conditions: Certain genetic disorders present from birth, such as Down syndrome and Apert syndrome, are associated with macroglossia.

Mechanical and Behavioral Factors

Sometimes, the cause is related to physical habits or issues with your jaw and teeth.

• Bruxism (Teeth Grinding and Clenching): This is a leading cause of scalloping. The constant pressure from grinding or clenching forces the tongue against the teeth, especially during sleep.
• Parafunctional Habits: Actions like tongue thrusting (pushing the tongue against the teeth when swallowing or at rest) and cheek sucking can create indentations over time.
• Temporomandibular Joint (TMJ) Disorders: Misalignment or dysfunction in the jaw joint can cause a person to use their tongue to stabilize or position their jaw, leading to sustained pressure against the teeth.

Psychological Factors

Your mental state can have physical manifestations, and a scalloped tongue can be one of them.

• Anxiety and Stress: High levels of anxiety often lead to physical habits like jaw clenching and bruxism, which in turn cause tongue scalloping. You may not even be aware you're doing it [6].

Illustration showing how a restricted airway in sleep apnea can cause the tongue to press against the teeth.

The Link Between Scalloped Tongue and Sleep Apnea

The connection between tongue scalloping and obstructive sleep apnea (OSA) is a significant area of clinical interest because it provides a simple, visible clue for a serious and often undiagnosed condition.

According to a study published in Frontiers in Sleep, patients with a scalloped tongue were three times more likely to have severe OSA. The risk was even higher when combined with other clinical signs; the presence of both a scalloped tongue and a neck circumference of 40 cm or more increased the risk of severe OSA by 4.2 times [1].

The causal mechanism is twofold:

1. Enlarged Tongue (Macroglossia): Fat deposits at the base of the tongue can increase its size, narrowing the airway and causing it to press against the teeth.
2. Airway Compensation: During sleep, the body tries to prevent airway collapse by pushing the tongue forward and down, creating pressure against the dental arches.

This makes tongue inspection a valuable, accessible tool for doctors screening for sleep-disordered breathing.

When Should You See a Doctor?

A scalloped tongue on its own is not a medical emergency. However, because it can signal an underlying condition, it's wise to consult a doctor or dentist, especially if:

• The scalloping is a new development or seems to be getting worse.
• It is accompanied by other symptoms like pain, swelling, or changes in tongue color.
• You are experiencing other related symptoms such as fatigue, daytime sleepiness, snoring (suggesting sleep apnea), hair loss, weight gain (suggesting hypothyroidism), or jaw pain.

Diagnosing the cause typically involves a physical examination of your mouth and a review of your medical history. Your doctor may also order blood tests to check for thyroid issues or nutritional deficiencies. If sleep apnea is suspected, a sleep study (polysomnography) may be recommended.

How is a Scalloped Tongue Treated?

Treatment focuses on addressing the root cause, not just the tongue indentations. Once the underlying issue is managed, the scalloping often resolves or lessens.

• For Sleep Apnea: Treatment may include a Continuous Positive Airway Pressure (CPAP) machine, oral appliance therapy, or lifestyle changes.
• For Hypothyroidism: Thyroid hormone replacement medication can correct hormone levels and reduce swelling.
• For Nutritional Deficiencies: Your doctor may recommend dietary changes or supplements to correct the deficiency.
• For Bruxism and TMJ: A custom-fitted mouth guard or splint can protect your tongue and teeth from pressure during sleep.
• For Anxiety: Stress-management techniques, therapy, or medication can help reduce anxiety-related clenching.
• For Dehydration: Increasing your daily fluid intake is a simple and effective solution.

At home, you can help manage any discomfort by staying hydrated, practicing good oral hygiene, and avoiding irritants like tobacco and alcohol.

A scalloped tongue is more than just an interesting feature—it's a potential clue to your overall health. Paying attention to this sign and seeking professional advice can lead to an early diagnosis and treatment of underlying conditions, improving your health and well-being.

References

[1] Guimarães, F., et al. (2025). "Scalloped tongue: an additional, accessible and useful tool to detect severe obstructive sleep apnea?". Frontiers in Sleep. https://www.frontiersin.org/journals/sleep/articles/10.3389/frsle.2025.1652532/full [2] Healthline. (2017). "Scalloped Tongue: Causes, Treatment, and Diagnosis". https://www.healthline.com/health/scalloped-tongue [3] Medical News Today. (2017). "Scalloped tongue: Causes, symptoms, and treatment". https://www.medicalnewstoday.com/articles/scalloped-tongue [4] Cleveland Clinic. (2025). "Scalloped Tongue: Symptoms, Causes & Treatment". https://my.clevelandclinic.org/health/symptoms/scalloped-tongue [5] Woman's World via Yahoo Lifestyle. (2025). "Sneaky High Blood Pressure Symptoms Doctors Want You to Know". https://www.yahoo.com/lifestyle/articles/high-blood-pressure-symptoms-women-132922376.html [6] Peace of Mind Dental. (n.d.). "Decoding Scalloped Tongue: Causes, Symptoms, and Treatment". https://www.pomdental.com/decoding-scalloped-tongue-causes-symptoms-and-treatment-options/