Sublingual Gland — Explained by Medical Evidence, Not Myths

The sublingual gland is one of the major salivary glands and sits in the floor of the mouth, beneath the tongue. It produces saliva that lubricates the mouth, helps begin digestion and protects oral tissues; most changes in this area are treatable, but persistent swelling or pain should be assessed by a clinician.

Overview: what is the sublingual gland?

The sublingual gland is a salivary gland located on each side of the floor of the mouth, underneath the tongue. It is the smallest of the three pairs of major salivary glands. The other major glands are the parotid glands, located in front of and below the ears, and the submandibular glands, located beneath the lower jaw.

Its main role is to make saliva, especially a thicker, mucus-rich type of saliva. This fluid keeps the mouth comfortable, moistens food for swallowing, begins the digestive process and helps protect teeth and oral tissues. Although people may notice the gland only when there is discomfort or swelling, it normally works continuously without being felt.

The sublingual gland releases saliva through many small ducts, often called ducts of Rivinus, which open along a fold of tissue under the tongue. In some people, a larger duct also joins or opens near the duct of the submandibular gland. This anatomy helps explain why swelling in the floor of the mouth should be examined carefully rather than self-diagnosed.

How the sublingual gland supports oral health

Saliva is more important than simply making the mouth feel wet. It helps wash away food debris, buffers acids produced by oral bacteria and supplies minerals that support tooth enamel. Saliva also makes speaking, tasting, chewing and swallowing easier. When saliva production is reduced, the mouth may feel sticky, dry or sore.

The sublingual gland contributes a smaller volume of saliva than some other major salivary glands, but its mucus-rich secretion is valuable for lubrication. Saliva output naturally rises with eating, smelling or thinking about food. It may decrease during sleep, dehydration, illness or anxiety.

A common myth is that all mouth dryness or under-tongue discomfort comes from the sublingual gland. In practice, dry mouth and mouth symptoms can have many causes, including medicines, mouth breathing, dehydration, diabetes, autoimmune conditions, tobacco use and problems affecting other salivary glands. A clinician considers the whole pattern of symptoms rather than assuming one gland is responsible.

Possible symptoms and changes under the tongue

A healthy sublingual gland is usually not noticeable. Changes that may prompt attention include a soft swelling beneath the tongue, soreness, tenderness, a feeling of fullness, dry mouth or discomfort while eating. Symptoms may occur on one side or both sides, and may be intermittent or persistent.

A swelling that becomes more noticeable around mealtimes can sometimes suggest reduced saliva drainage. Saliva may build up behind a narrowed or blocked duct, causing pressure or pain when the gland is stimulated. However, stones are much more common in the submandibular gland than in the sublingual gland, so an examination is needed to identify the source accurately.

A bluish, clear or dome-shaped swelling in the floor of the mouth may be a ranula. This is a mucus collection that can develop when saliva leaks from or cannot drain through a sublingual gland duct. Small ranulas may cause little discomfort, while larger ones can affect speech, chewing or swallowing. Not every lump under the tongue is a ranula, so a new or persistent swelling should be evaluated.

• Dryness, stickiness or thick saliva in the mouth
• Pain or swelling that occurs during meals
• A tender area, redness or discharge in the floor of the mouth
• A lump that remains longer than two weeks or continues to grow
• Difficulty moving the tongue, swallowing or speaking normally

Causes of sublingual gland problems

Reduced saliva flow or blockage of a salivary duct can lead to gland swelling and discomfort. This may result from thickened saliva, dehydration, local inflammation, narrowing of a duct or, less often, a salivary stone. Good fluid intake can support normal saliva flow, but it does not replace evaluation when swelling is recurrent, painful or persistent.

Infections can affect salivary glands, particularly when saliva flow is low. A bacterial infection may cause pain, swelling, tenderness, fever or a bad taste if pus drains into the mouth. Viral illnesses can also cause salivary gland swelling, more commonly involving other glands. Dental infections, oral injuries and poor oral hygiene may contribute to inflammation in nearby tissues.

Some medicines can cause dry mouth, including certain treatments for allergies, depression, bladder symptoms, pain and blood pressure. Radiation treatment to the head and neck, autoimmune conditions such as Sjögren’s disease and systemic illnesses can also reduce saliva production. A clinician may review medicines and medical history when symptoms suggest an underlying cause.

Benign growths and cancers of the salivary glands are uncommon, particularly in the sublingual gland, but any firm, persistent or enlarging mass needs professional assessment. The presence of a lump does not automatically mean cancer. Early review helps identify the cause and guide appropriate care.

How clinicians diagnose a sublingual gland concern

Assessment usually begins with a medical and dental history. The clinician may ask when the swelling began, whether it changes with meals, if there is dryness or fever, and which medicines the person uses. They will examine the mouth, floor of the mouth, tongue, teeth, neck and nearby salivary gland openings.

Sometimes gentle pressure on a salivary gland duct helps the clinician check whether saliva is flowing normally and whether there is tenderness or discharge. The examination may also help distinguish a salivary gland problem from a dental condition, a cyst, an enlarged lymph node or another oral tissue change.

If more information is needed, imaging may be recommended. Ultrasound is often useful for assessing superficial salivary gland swelling and cysts. Depending on the concern, CT, MRI or other specialized imaging may offer a clearer view of deeper structures or a possible stone. A sample of fluid or a tissue biopsy may be considered when a lesion needs further clarification.

People should avoid attempting to puncture, squeeze or drain an under-tongue swelling at home. This can cause injury or infection and can make accurate assessment more difficult.

Treatment, prevention and self-care

Treatment depends on the cause. For mild dryness or temporary reduction in saliva flow, a clinician may recommend regular hydration, good oral hygiene, avoiding tobacco and limiting alcohol-containing mouth rinses that can worsen dryness. Sugar-free gum or sugar-free lozenges may stimulate saliva for some people, provided there is no painful swelling that could reflect obstruction.

If a medicine is contributing to dry mouth, the prescribing clinician can consider whether an alternative is appropriate. People should not stop prescribed medicine on their own. Regular dental care is especially important with dry mouth because reduced saliva can increase the risk of tooth decay, gum problems and oral discomfort.

When there is an infection, a clinician may provide treatment based on the suspected cause and severity. A confirmed blockage, recurrent ranula or persistent lesion may need care from an ENT specialist or oral and maxillofacial surgeon. Procedures can range from addressing an obstruction to treating the cyst or, in selected cases, removing the affected gland. The best approach depends on symptoms, anatomy and imaging findings.

Acibadem International’s multidisciplinary specialists and JCI-accredited hospitals evaluate salivary gland concerns and coordinate treatment for international patients when specialist care is needed.

When to seek medical care

It is sensible to arrange a dental or medical assessment for a new swelling under the tongue that does not settle, returns repeatedly or lasts more than about two weeks. Review is also appropriate for pain during meals, ongoing dry mouth, a bad taste or discharge in the mouth, unexplained bleeding, numbness, or a firm and enlarging lump.

Prompt medical care is important if swelling becomes rapidly larger, there is fever with significant mouth pain, or the person has difficulty swallowing fluids. Emergency care is needed for any trouble breathing, severe tongue or floor-of-mouth swelling, inability to handle saliva, confusion or signs of a serious allergic reaction.

Most salivary gland symptoms have non-cancerous and manageable explanations. Still, an in-person examination is the safest way to determine whether reassurance, simple self-care, dental treatment, medicines, imaging or specialist referral is appropriate.

Frequently asked questions

Where is the sublingual gland located?

The sublingual gland sits in the floor of the mouth, under the tongue. There is one gland on each side, and they release saliva through multiple small openings beneath the tongue.

Can a person feel a normal sublingual gland?

Most people do not notice a normal sublingual gland. A new lump, visible swelling, tenderness or a persistent feeling of fullness beneath the tongue should be examined by a dentist or clinician.

What is a ranula?

A ranula is a mucus-filled swelling in the floor of the mouth, often related to saliva leaking from or being blocked in a sublingual gland duct. It may look bluish or translucent and can be painless, but larger ranulas may interfere with eating, speech or swallowing.

Does pain under the tongue mean there is a salivary stone?

Not necessarily. Salivary stones can cause pain and swelling, especially during meals, but they are more often found in the submandibular gland than in the sublingual gland. Infection, irritation, a cyst, dental problems and other conditions can cause similar symptoms.

Can dehydration affect the sublingual gland?

Dehydration can reduce saliva flow and make saliva thicker, which may contribute to dry mouth and discomfort. Drinking enough water may help, but recurring swelling, significant pain or persistent dryness should still be discussed with a healthcare professional.

Are sublingual gland tumors common?

Tumors of the sublingual gland are uncommon. Even so, a firm, growing, persistent or unexplained lump requires timely clinical assessment so that the cause can be identified.

References

• National Institute of Dental and Craniofacial Research
• American Dental Association
• Merck Manual Consumer Version
• Mayo Clinic
• National Health Service

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.