Airway symptoms and rapidly spreading infection need immediate assessment
Do Not Wait for a Routine Scan if Breathing or Swallowing is Affected
Go for urgent or emergency assessment if you have:
- Difficulty breathing, noisy breathing, choking or a rapidly changing voice.
- Inability to swallow saliva, drooling or rapidly worsening swallowing difficulty.
- Rapid swelling beneath the jaw, beneath the tongue or in the floor of the mouth, especially if the tongue is being pushed upwards.
- High fever with spreading redness, severe neck pain, marked drowsiness, confusion or severe weakness.
- Rapidly increasing swelling with inability to drink, very little urine or other signs of dehydration.
- A pulsating lump, active bleeding or major swelling after facial or neck trauma or a procedure.
Deep infection can threaten the airway and may require urgent examination, intravenous treatment, CT and drainage. A routine outpatient ultrasound should not delay that care.
What is Salivary-Gland Ultrasound?
Saliva is made by many glands and reaches the mouth through small tubes called ducts. The paired parotid glands lie in front of and just below the ears; their ducts cross each cheek. The paired submandibular glands lie beneath the jaw; their ducts travel forwards to open under the tongue. The smaller sublingual glands sit in the floor of the mouth.
A high-frequency probe creates real-time images through the skin. Grey-scale ultrasound assesses gland texture, ducts and focal lesions; colour Doppler records detectable blood flow. The radiologist usually compares both sides because symmetry and the unaffected gland provide useful context.
The Meal-Time Pattern is an Important Clue
Pain or swelling that appears or worsens when eating suggests impaired saliva drainage. A stone is common, but duct narrowing, scarring or a mucus plug can produce the same pattern. A scan that shows no stone does not by itself exclude obstruction.
When Should a Salivary Lump Be Reviewed Promptly?
Arrange timely ENT, oral and maxillofacial or head-and-neck assessment if:
- A painless lump near the ear, cheek, jaw or floor of the mouth is persistent or increasing.
- The lump feels firm or fixed, the skin becomes tethered or ulcerated, or the swelling returns after treatment.
- There is new weakness of one side of the face, facial numbness or difficulty closing an eye.
- There is persistent pain, difficulty opening the mouth, swallowing difficulty or one-sided ear pain.
- A neck lymph node appears or enlarges, or there is unexplained weight loss.
- You have had a previous salivary tumour, head-and-neck cancer or radiation treatment to the area.
These features do not prove cancer—many parotid tumours are benign—but they should not be managed by repeated antibiotics or observation without a clear diagnosis. Facial weakness with a parotid-region mass is particularly important and requires prompt specialist review.
How is This Different From Other Salivary Tests?
Why Might the Scan Be Requested?
Other reasons can include:
- Repeated parotid or submandibular swelling, with or without visible stones.
- Possible chronic sialadenitis, duct scarring or gland damage.
- Dry mouth and recurrent gland swelling in suspected Sjögren disease or another autoimmune condition.
- Parotitis in a child or recurrent juvenile parotitis.
- A salivary abnormality found on dental imaging, CT, MRI, PET or another ultrasound.
- Follow-up of a known benign-appearing lesion or treated salivary-gland condition.
- Evaluation of adjacent cervical lymph nodes when a gland tumour is suspected.
Dry mouth alone has many possible causes, including medicines, dehydration and systemic disease. Ultrasound may contribute to the assessment but does not measure saliva production or diagnose Sjögren disease by itself.
What Does the Radiologist Assess?
What Conditions May Be Found?
How Should I Prepare?
No fasting, full bladder or medicine change is usually needed for diagnostic salivary-gland ultrasound. A biopsy or another scan booked at the same visit may have separate instructions.
- Say whether swelling is triggered by meals or sour food and how long it takes to settle.
- Point to the exact lump, even if the swelling has disappeared by the appointment.
- Mention dry mouth, dry eyes, fever, bad taste, pus, dental problems and recent dehydration or illness.
- Report facial weakness, numbness, rapid growth, swallowing difficulty and difficulty opening the mouth.
- Do not repeatedly squeeze a painful swelling or attempt to remove a deep stone with a sharp object.
What Happens During the Scan?
You describe whether symptoms are meal-related, painful, recurrent or associated with dry mouth, discharge, fever, a persistent lump or facial symptoms.
You usually lie on your back with the neck supported. The position is adapted if extension is painful or difficult.
Gel is placed in front of and below each ear and along the cheek. The superficial parotid tissue and visible duct are scanned in several planes.
The probe moves beneath the jaw and towards the floor of the mouth. Both sides are compared for stones, duct widening, inflammation and focal lesions. The probe normally remains on the skin.
Blood flow, any visible stone, collection, mass and relevant lymph nodes are documented. Gentle pressure can be tender when the gland is inflamed.
The report may suggest clinical treatment, ENT or oral and maxillofacial review, CT, MRI, sialendoscopy, follow-up ultrasound, FNA or core biopsy.
The examination usually takes about 20–30 minutes. Multiple lumps, previous surgery or an added neck-node or thyroid assessment may require longer.
What Do Common Report Terms Mean?
What Can Ultrasound Not Determine Reliably?
- Every tiny stone, non-calcified mucus plug, intermittent blockage or duct stricture.
- The entire parotid duct, deep parotid lobe, floor-of-mouth ducts or minor salivary glands hidden by bone and air.
- The exact benign or malignant tumour type from appearance and Doppler flow alone.
- That a mass is benign simply because it is painless, well defined or has little detectable blood flow.
- Perineural spread along the facial nerve, skull-base involvement or the full extent of a deep tumour.
- The complete extent of a deep-neck infection or every drainable collection without CT or MRI.
- Sjögren disease or another autoimmune condition without the clinical, laboratory and specialist context.
- Normal duct function between episodes when meal-related swelling is intermittent.
A normal or reassuring scan should be reconsidered when the lump grows, facial function changes or a strong meal-related obstruction pattern continues. The next useful test may be CT, MRI, MR sialography, sialendoscopy or tissue sampling rather than repeated ultrasound alone.
When is a Needle Sample Recommended?
Sampling may be advised for a persistent solid salivary mass, an indeterminate lesion, a suspicious lymph node or an abnormality that would change treatment. The biopsy plan depends on the likely diagnosis and location.
A diagnostic scan booking does not automatically include a needle procedure. Do not stop blood-thinning medicine unless the procedure team has reviewed it and given an individual plan.
What Happens After the Scan?
You can wipe away the gel and resume normal food, drink, medicines and activity. The report describes the gland, visible duct, any stone or focal lesion, Doppler findings and relevant lymph nodes and states whether further investigation is recommended.
A visible stone may lead to hydration and symptom treatment, duct massage advice, ENT or oral and maxillofacial review, sialendoscopy or another procedure depending on size and location. Infection may need clinical treatment; an abscess or deep infection may require urgent CT and drainage. A mass may need FNA or core biopsy and MRI or CT.
Seek earlier review if swelling rapidly worsens, fever develops, you cannot drink, swallowing or breathing becomes difficult, or facial weakness appears. Antibiotics can treat bacterial infection but do not remove an obstructing stone.
Myth vs Fact
Frequently Asked Questions
Do I need to fast?
Usually not. Eat, drink and take regular medicines normally unless another scan, sedation or biopsy has separate instructions.
Will the scan hurt?
It is usually comfortable, although gentle probe pressure can be tender over an acutely inflamed gland. Tell the radiologist if pain is severe or rapidly worsening.
Does the probe go inside my mouth?
A standard examination is performed through the skin around the ear, cheek, jaw and upper neck. Clinical inspection inside the mouth may be important, but an internal ultrasound probe is not routinely used.
Can ultrasound detect every salivary stone?
No. It detects many stones, particularly when they are accessible and create a clear acoustic shadow, but very small, distal or difficult-to-reach stones and non-stone obstructions can be missed.
Why might I need CT or MRI after ultrasound?
CT can better show calcified stones and deep infection. MRI better maps deep-lobe masses, nerves and the skull base. The best next test depends on whether the problem is obstruction, infection or a tumour.
Can the scan tell whether a lump is cancer?
It can identify features that raise or reduce concern and guide a needle safely, but it usually cannot prove the exact tumour type. FNA or core biopsy and sometimes MRI or CT provide the definitive pathway.
Will a biopsy be performed at the same appointment?
Only if it was specifically requested, planned and consented. A diagnostic scan alone does not automatically include FNA, core biopsy or drainage.
Should I suck lemon or a sour sweet before the scan?
Not unless the imaging team asks you to. A saliva stimulant can reproduce obstruction and may be useful in a controlled part of selected examinations, but it can also trigger marked pain and swelling.
Can ultrasound diagnose Sjögren disease?
Not by itself. A characteristic gland pattern may support the assessment, but dry-eye and dry-mouth symptoms, examination, blood tests and specialist review remain essential.
When will I receive the result?
The radiologist prepares a report for the referring clinician. Significant or urgent findings are communicated through the appropriate pathway. Ask how and when the result will be discussed.