A tender, swollen lump in front of the ear or under the jaw that gets worse when you eat is often a salivary gland that has become inflamed or infected. Doctors call this sialadenitis. In most cases the trouble starts because saliva has stopped flowing freely through the gland, so getting it moving again is the main part of treatment, with antibiotics added when bacteria are involved.
Where your salivary glands are
There are three pairs of large salivary glands. The parotid glands sit in front of and just below each ear. The submandibular glands lie under the jawbone towards the back, and the smaller sublingual glands sit under the tongue. Each one drains saliva into the mouth through a small duct. The parotid duct opens on the inside of the cheek near the upper back teeth, and the submandibular ducts open under the tongue near the front.
Sialadenitis most often affects the parotid gland. The submandibular gland is also commonly involved, particularly when a stone blocks its duct. When a gland is inflamed it swells, aches and may feel firm to touch.
Sluggish saliva lets infection in
The MSD Manual notes that sialadenitis usually follows reduced saliva production or a blocked duct, although it sometimes appears without an obvious cause. When saliva sits still in a duct, bacteria from the mouth can travel back up into the gland. The most common bacterium involved is Staphylococcus aureus.
Things that can slow or block the flow include:
- a salivary stone lodged in the duct, which is a frequent cause of gland swelling and tends to flare at mealtimes
- a narrowed duct from earlier inflammation or scarring
- a dry mouth from illness, some medicines, radiation treatment or conditions such as Sjögren's syndrome
- not drinking enough, particularly during an illness
Viruses can also inflame the glands directly. Mumps is the best known, and it often causes swelling of the parotid glands on one or both sides. Viral cases usually settle on their own with supportive care.
If a stone is the likely cause, our guide to salivary gland stones explains the pattern of swelling around meals in more detail. Because dry mouth plays such a large part, we also cover Sjögren's syndrome and dry mouth in separate articles.
Signs to look for
The usual picture is a painful, swollen gland that is tender to press. Some people notice a bad taste, or see pus coming from the opening of the duct inside the mouth. A bacterial infection often comes on quickly and may bring a temperature and redness over the gland. Swelling on both sides at once is more typical of a viral cause. Pain and swelling that build each time you eat point towards a blockage.
Longer-term, or chronic, sialadenitis tends to cause repeated episodes of swelling, often linked to a stone or a narrowed duct, and the skin over the gland may not look red.
Treatment aims to get saliva flowing
For most people, the first steps are simple and done at home under the guidance of a doctor or dentist:
- drink plenty of water
- hold a warm compress against the swollen gland
- gently massage the gland in the direction of its opening in the mouth
- suck on sour, sugar-free lollies or a little lemon to encourage saliva
- keep brushing and cleaning carefully, as good oral hygiene helps recovery
When the infection is bacterial, antibiotics are prescribed. They do not help viral causes such as mumps. A firm, localised swelling that keeps growing may be an abscess, which needs to be drained.
If a stone or narrowed duct keeps causing trouble, the next step depends on where it sits. Small stones near the opening can sometimes be massaged out. Other options, usually provided by a head and neck surgeon, include sialendoscopy, where a very fine camera is passed into the duct to find and remove stones or widen a narrowing. Removing the gland is reserved for a small number of people with repeated, troublesome infections.
Get help quickly if the swelling is spreading
Most episodes are uncomfortable rather than dangerous. Seek urgent medical care, through your GP, an after-hours service or an emergency department, if:
- the swelling is spreading across your face or down your neck
- the area is hot and enlarging quickly
- you have a high temperature or feel very unwell
- you have any difficulty swallowing, opening your mouth or breathing
These can be signs that infection is spreading, which needs prompt treatment. The same warning signs apply to a spreading dental infection, so a dentist or doctor should check any facial swelling that is getting worse.
Lowering the chance of it coming back
Because poor flow is the common thread, prevention is mostly about keeping saliva moving. Stay well hydrated, especially in hot weather or when you are unwell. Keep up careful brushing and cleaning between your teeth. If you have a condition or medicine that dries your mouth, ask your doctor or dentist about ways to manage it, and if you have had a stone before, mention any new swelling early.
What patients ask about swollen salivary glands
Should I see a dentist or a doctor?
Either can be a good starting point. A GP can assess the gland and prescribe antibiotics if needed. A dentist can check whether a tooth or gum problem is causing swelling near the jaw, look at the duct openings inside the mouth, and take X-rays that may show a stone. If you are unwell or the swelling is spreading, seek medical care urgently.
How can I tell a swollen gland from a tooth abscess?
It is not always easy. A gland that swells around meals and sits in front of the ear or under the jaw points towards the salivary gland, while swelling with a painful tooth or a gum boil points towards a dental cause. An examination and X-rays help sort out which it is.
Can it come back?
Yes, especially if a stone, a narrowed duct or a dry mouth keeps slowing saliva. Treating the underlying cause and staying hydrated lower the chance of repeat episodes.
A sore, swollen salivary gland usually settles once saliva is flowing again and any infection is treated. If yours is not improving or keeps returning, the team at Lumi Dental in Melrose Park can examine the area, check for a dental cause and help with the next step. You can read more about our general dental care.
