Swollen Salivary Glands: Why It Happens and What to Do

“Salivary glands are exocrine structures responsible for producing saliva, a biological fluid essential for several functions. Saliva initiates the digestive process through specific enzymes, lubricates the oral cavity facilitating chewing and swallowing, protects the mucous membranes, and contributes to maintaining the balance of oral bacterial flora,” explains Prof. Giordano.

An alteration in saliva production or an obstruction of the excretory ducts may lead to:

• saliva stagnation
• inflammation
• a consequent increase in the volume of the affected gland.

The major salivary glands most commonly involved are:

• the parotid glands
• the submandibular glands
• the sublingual glands

Among these, parotid and submandibular glands are the ones most frequently affected by swelling. In addition, there are also minor salivary glands, which may also become swollen.

Parotid glands

The parotid glands are the largest salivary glands. They are located in front of and below the ears and produce a fluid saliva rich in digestive enzymes. Saliva reaches the oral cavity through the Stensen’s duct, which passes through the cheek and opens near the second upper molar.

When the parotid gland becomes swollen, the enlargement is visible on the side of the face. This gland is frequently involved in infections but is also the most common site for salivary gland tumors, which are benign in most cases.

Sublingual glands

The sublingual glands are smaller and located beneath the tongue. They contribute less to overall saliva production.

They may develop mucous cysts, known as ranulas. Swelling of these glands is less common but, when it occurs, it mainly causes discomfort or a feeling of tension in the floor of the mouth.

Submandibular glands

The submandibular glands are located beneath the jaw and produce a significant portion of daily saliva, which has both serous and mucous components.

They are the glands most frequently affected by salivary stones (sialolithiasis) due to the characteristics of the saliva they produce and the upward course of the Wharton’s duct, which opens in the floor of the mouth near the lingual frenulum.

Minor salivary glands

In addition to the major glands, numerous minor salivary glands are distributed throughout the mucosa of the lips, cheeks, palate, and floor of the mouth. They continuously contribute to the lubrication of the oral cavity.

When the duct of a minor salivary gland becomes blocked or ruptures, a mucocele may develop, a small collection of saliva that appears as a soft swelling, often bluish and translucent, most commonly on the lower lip.

“The causes of salivary gland swelling can be multiple. The most common are infections, both viral and bacterial, known as sialadenitis,” continues Prof. Giordano.

Other causes include:

• salivary stones that obstruct saliva flow
• dehydration
• reduced saliva production (often linked to certain medications)
• autoimmune diseases
• neoplastic lesions, which are less common.

From a clinical perspective, certain signs help guide diagnosis. Painful swelling that worsens during meals suggests an obstructive cause: saliva is produced but cannot drain properly. Swelling associated with fever, redness, and persistent pain instead points toward an infectious process.

There is no single prevalence figure for all forms of salivary gland swelling, since it is a clinical sign rather than a single disease. However, sialadenitis represents a significant proportion of cases seen in clinical practice, particularly among older individuals and those with reduced salivary flow.

Poor oral hygiene, smoking, and alcohol consumption also play a contributing role, as reduced saliva flow and changes in oral bacterial balance create favorable conditions for infection.

Symptoms vary depending on the underlying cause.

“In inflammatory conditions such as sialadenitis:

• swelling is often painful
• it appears rapidly
• it may be accompanied by fever and skin redness
• it may involve one gland or both, especially in viral infections.

A typical example is mumps, a viral infection that mainly affects the parotid glands and presents with bilateral swelling, fever, and general malaise,” explains the specialist.

Tumors, which are benign in most cases, usually present with:

• unilateral swelling
• slow growth
• absence of pain
• no fever.

Malignant forms, which are rarer, may present with:

• a hard, fixed swelling
• sometimes associated with persistent pain or changes in facial sensation or movement.

In summary, pain, fever, and bilateral swelling suggest an inflammatory cause, while isolated, painless, persistent swelling always requires specialist evaluation.

In mild cases, with moderate swelling and no fever, conservative measures may be attempted:

• increase hydration
• stimulate saliva production with sugar-free candies or citrus fruits
• apply warm compresses
• maintain good oral hygiene.

Non-steroidal anti-inflammatory drugs (NSAIDs) may also be used for a short period to reduce pain and inflammation.

These measures can be tried for 2–3 days, carefully monitoring symptom progression. If swelling decreases and pain improves, conservative management may continue.

However, if swelling persists, worsens, or fever appears, it is necessary to consult a physician. Taking antibiotics or corticosteroids without medical guidance is not recommended, as inappropriate treatment may mask symptoms and delay diagnosis.

An ENT evaluation is recommended when:

• swelling does not resolve spontaneously
• symptoms persist for more than a few days
• pain is severe or accompanied by fever
• swelling is unilateral, hard, and painless
• the mass progressively increases in size.

“The ENT specialist performs a targeted clinical evaluation and, if necessary, may request imaging tests such as ultrasound, CT scan, or MRI, which are essential for guiding diagnosis and defining the appropriate treatment pathway,” he adds.

A particularly important aspect concerns the close anatomical relationship between the parotid gland and the facial nerve, which controls facial movements. In this region also runs the marginal mandibular nerve, responsible for movements of the lower lip.

“For this reason, in the presence of a nodule or salivary gland disease, especially involving the parotid gland, a thorough specialist evaluation is essential. Any treatment, particularly surgical treatment, must preserve the integrity of the nerve structures in order to maintain facial function and expression,” concludes Prof. Giordano.