The gland sitting just behind and below your ear is the parotid gland, the largest of the three pairs of major salivary glands. It wraps around the back edge of the jawbone on each side of your face, tucked between the ear canal and the angle of the jaw, and its main job is producing saliva that flows through a duct into your mouth near your upper molars. When people notice a puffy, tender, or firm lump in that area, the parotid gland is usually the structure involved, though swollen lymph nodes in the same neighborhood can feel similar and cause confusion.
Where the Parotid Gland Actually Sits
The parotid gland is roughly wedge-shaped and sits in front of and slightly below each ear. It drapes over the back of the jawbone and extends forward along the cheek. One reason it matters so much surgically is that the facial nerve, the nerve responsible for moving the muscles of your face, runs directly through it, splitting into branches inside the gland tissue itself.1PubMed Central. Facial Nerve and Parotid Gland Anatomy That intimate relationship between gland and nerve is why parotid problems sometimes affect facial movement, and why surgeons treat the area with particular care.
Your other two pairs of major salivary glands, the submandibular glands under the jaw and the sublingual glands beneath the tongue, produce saliva as well, but the parotid is the one you feel when something goes wrong behind the ear. Most of the time you are completely unaware of it. It quietly secretes a watery, enzyme-rich saliva that helps break down starches while you chew. It only announces itself when it swells.
Why It Gets Mistaken for a Swollen Lymph Node
There are several lymph nodes clustered around and even embedded within the parotid gland. Because of that overlap, a swollen parotid is frequently mistaken for swollen lymph nodes, and vice versa. One clinical review noted that parotid swellings are often confused with cervical lymph node enlargement, and this mix-up can delay accurate diagnosis.2BMJ. Salivary gland swellings A simple rule of thumb: lymph nodes tend to feel like small, discrete, movable lumps, while a swollen parotid tends to produce a broader, more diffuse fullness that lifts the earlobe slightly and fills the space between the jaw and ear. If you can roll the lump between your fingers easily, it is more likely a lymph node. If the entire area below your ear feels puffy, especially if it is tender and worse at mealtimes, the parotid gland itself is the more likely culprit.
Mumps and Other Infections
The classic infectious cause of parotid swelling is mumps. Mumps virus targets the parotid glands specifically, causing them to swell on both sides in most cases. The swelling typically shows up two to three weeks after exposure, lasts a few days to over a week, and gives the face a characteristic chipmunk-cheeked look.3PubMed Central. Molecular biology, pathogenesis and pathology of mumps virus During the infection, the virus replicates inside the gland, triggering inflammation, tissue swelling, and destruction of some of the saliva-producing cells. The person is contagious from about a week before the swelling appears to a week after it starts.
Widespread vaccination has made mumps far less common than it once was, but outbreaks still happen, particularly in settings with close contact. And mumps is not the only infection that can inflame the parotid. Bacterial parotitis, sometimes called suppurative parotitis, occurs when bacteria travel up the salivary duct into the gland. It tends to strike people who are dehydrated, post-surgical, elderly, or immunocompromised. The gland becomes swollen, hot, and very painful, often on just one side, and pus may drain from the duct opening inside the mouth. Treatment focuses on rehydration, antibiotics, and maintaining good oral hygiene.4PubMed. Acute bacterial suppurative parotitis: microbiology and management Other viruses, including influenza, Epstein-Barr, and HIV, can also cause parotid inflammation, though less commonly than mumps.
Salivary Stones and Duct Blockages
A surprisingly common reason for parotid swelling is a salivary stone, a hard calcium deposit that forms inside the duct and blocks the flow of saliva. When you start eating, the gland ramps up production, but the saliva has nowhere to go, so the gland balloons painfully. The pain and swelling spike at mealtimes and gradually ease between meals. Stone formation appears to be driven by a combination of factors including changes in saliva composition, tiny seed crystals, and bacteria.5PubMed Central. Parotid sialolithiasis
Stones are more common in the submandibular gland than in the parotid, but parotid stones do occur and can be especially tricky because the duct is longer and more winding. Small stones sometimes pass on their own, especially if you encourage saliva flow. One study found that sour stimuli like pure lemon juice and malt vinegar were among the most effective at promoting saliva production during a controlled test, generating roughly 20 to 24 milliliters of saliva in just five minutes.6PubMed Central. Sialagogues: A Sour Solution to Sialolithiasis Sucking on sour candies works similarly. For stones that will not budge, doctors can use sialendoscopy, a procedure where a tiny camera is threaded into the duct to locate and remove the stone. In experienced hands, this approach succeeds in about 85% of cases, and only a small percentage of patients ultimately need the gland removed.7PubMed. Specificity of parotid sialendoscopy8PubMed Central. Sialendoscopy for salivary stones: principles, technical skills and therapeutic experience
Autoimmune Swelling and Sjögren Syndrome
When parotid swelling keeps coming back without an obvious infection or stone, an autoimmune condition may be the underlying cause. Sjögren syndrome is the most well-known example. It is a systemic autoimmune disease in which the body’s immune cells attack the moisture-producing glands, particularly the salivary and tear glands, leading to severe dryness of the mouth and eyes.9Nature Reviews Disease Primers. Sjögren syndrome The damage is driven by abnormal immune responses targeting specific proteins within the gland tissue.
Parotid swelling in Sjögren syndrome can be intermittent or persistent. When biopsied, the swollen tissue typically shows characteristic changes. In one study of patients who required a parotid biopsy during their workup, the most common finding was a specific pattern of immune cell infiltration called lymphoepithelial lesions, though a small number turned out to have lymphoma.10Rheumatology. Parotid gland swelling in primary Sjögren’s syndrome: activity and other sialadenosis causes That lymphoma risk, though low, is one reason chronic or recurrent parotid swelling in Sjögren patients is taken seriously and monitored.
Eating Disorders and Other Metabolic Causes
A less widely known cause of parotid enlargement is bulimia nervosa. Repeated self-induced vomiting stimulates the parotid glands abnormally, and over time they enlarge, sometimes dramatically. The swelling is usually painless and bilateral, giving the face a rounded appearance. This condition, called sialadenosis, reflects a non-inflammatory enlargement of the gland cells rather than infection or obstruction.11PubMed Central. Bilateral Parotid Sialadenosis Associated with Long-Standing Bulimia: A Case Report and Literature Review It can persist for years if the underlying eating disorder continues.
Other metabolic conditions can cause similar painless enlargement. Chronic alcohol use, diabetes, malnutrition, and certain hormonal imbalances have all been linked to parotid sialadenosis. In these cases the gland is not infected or blocked; instead, the individual gland cells swell. The enlargement tends to resolve if the underlying condition is treated, though it can take months.
Parotid Tumors
Not all parotid lumps are inflammatory. The parotid is the most common site for salivary gland tumors. The reassuring news is that the majority are benign. The most frequent type is pleomorphic adenoma, a slow-growing, painless lump that accounts for roughly 65% of all salivary gland tumors.12PubMed Central. Pleomorphic adenoma presenting with conductive hearing loss in the ear canal: a case report and review of the literature It typically shows up as a firm, mobile mass that has been growing slowly for months or even years. Most people notice it only when it becomes large enough to see or feel.
Malignant parotid tumors are less common but more concerning. The most frequent malignant type is mucoepidermoid carcinoma.13Jurnal Ilmu Kesehatan Indonesia. Karakteristik Klinis dan Patologis Pasien Tumor Parotis di RSUP Dr. M. Djamil Padang Warning signs that a parotid lump may be cancerous include rapid growth, pain, fixation to surrounding tissue, skin changes over the lump, and especially weakness or paralysis of part of the face. Because the facial nerve runs through the gland, a tumor that invades the nerve can cause drooping of the mouth, inability to close the eye, or other facial movement problems. In one large study, facial nerve weakness at the time of diagnosis was one of the strongest predictors of a worse outcome, reducing five-year disease-free survival nearly tenfold compared to patients without nerve involvement.14PubMed. Signs and symptoms of parotid gland carcinoma and their prognostic value Pain and enlarged neck lymph nodes are also common presentations of parotid malignancies, present in roughly 40% and 32% of cases respectively.
How Doctors Evaluate a Parotid Lump
If you show up with a lump behind your ear, the first step is usually a physical exam followed by an ultrasound. Ultrasound is quick, noninvasive, and widely available, and it gives a good initial picture of whether the lump is within the parotid gland, how large it is, and whether it has features that suggest a benign or malignant process.15PubMed Central. Cross-sectional Imaging of Parotid Gland Nodules: A Brief Practical Guide When more detail is needed, MRI is the preferred imaging tool, particularly because it shows soft tissue contrast well and can help delineate the relationship between a mass and the facial nerve. One retrospective study found that combining ultrasound and MRI achieved the highest diagnostic accuracy, with a specificity over 94% for distinguishing benign from malignant tumors.16PubMed Central. Diagnostic accuracy of ultrasound and MRI in parotid gland tumors: A retrospective study
For lumps that need a tissue diagnosis, fine needle aspiration is the standard first step. A thin needle is inserted into the lump and cells are drawn out for examination under a microscope. It is good at confirming benign disease, with a sensitivity around 85%, but it is less reliable at catching malignancies, where its sensitivity drops to about 52%.17PubMed Central. The diagnostic value of fine needle aspiration in parotid lumps That means a negative result does not completely rule out cancer, and if clinical suspicion remains high, further investigation including surgical biopsy may follow.
Parotid Swelling in Children
Children get parotid swelling too, and not just from mumps. Juvenile recurrent parotitis is the second most common inflammatory condition of the parotid gland in children, after mumps. It involves repeated episodes of non-infectious parotid swelling, typically on one side, with pain and sometimes low-grade fever. The episodes tend to start in early childhood and recur unpredictably.18PubMed Central. Juvenile recurrent parotitis The cause remains unclear. Theories range from congenital duct abnormalities to immune dysfunction to low-grade ascending infections. The good news is that most children outgrow it by puberty, though some continue to have episodes into adulthood. Treatment during flares is supportive: hydration, warm compresses, gentle massage of the gland, and sometimes antibiotics if bacterial infection is suspected.
When Eating Makes Your Skin Sweat
One of the stranger complications related to the parotid gland is Frey syndrome, also known as gustatory sweating. It happens when nerve fibers that were damaged, usually by parotid surgery or sometimes by infection, regrow incorrectly. Instead of reconnecting to salivary gland tissue, the regenerating parasympathetic nerve fibers hook up with the sweat glands in the skin overlying the parotid region.19PubMed Central. Auriculotemporal Syndrome (Frey Syndrome) The result is that whenever you eat or even think about food, the skin in front of your ear flushes and sweats. The phenomenon was documented decades ago: researchers testing a patient’s skin with compounds that stimulate nerve endings concluded that misdirected parasympathetic fibers were driving the sweat glands to behave as though they were salivary tissue.20JAMA. Auriculotemporal Syndrome: Gustatory Sweating Due to Misdirection of Regenerated Nerve Fibers
Frey syndrome is not dangerous, but it can be socially awkward. Treatments include antiperspirant applied to the affected skin and, in more bothersome cases, botulinum toxin injections, which temporarily block the nerve signals to the sweat glands. It affects a meaningful percentage of people who undergo parotid surgery, though many cases are mild enough that they go unreported.
How Parotid Glands Compare Across Species
Humans are not the only animals with well-developed parotid glands. All mammals have them, but their size and the type of saliva they produce vary enormously depending on diet. A comparative study examining the parotid and mandibular glands of the lowland tapir and the aardvark found striking differences. The tapir’s parotid gland had large lobes of varied shapes, while the aardvark’s were smaller and more uniform. The chemical makeup of their saliva also differed, reflecting the tapir’s plant-heavy diet versus the aardvark’s insect-based one.21PubMed Central. Comparative Histology and Histochemistry of the Parotid Gland and Mandibular Gland in the Lowland Tapir and Aardvark Grazing animals tend to have the largest parotid glands relative to body size, because their saliva needs to buffer the acids produced by fermenting plant material. Carnivores, by contrast, have smaller parotid glands. The human parotid sits somewhere in the middle, reflecting our omnivorous diet and our reliance on salivary enzymes to begin starch digestion before food even reaches the stomach.
Practical Signs That Warrant a Doctor Visit
Most parotid swelling resolves on its own or with simple measures like hydration and warm compresses. But certain features should prompt a visit to a healthcare provider sooner rather than later:
- Rapid growth: A lump that appears over days or changes noticeably in weeks needs evaluation.
- Facial weakness: Any drooping of the mouth, difficulty closing an eye, or asymmetry of facial movement alongside a parotid lump raises concern for a malignant process.
- Persistent pain: Mild tenderness during a viral infection is expected, but worsening pain, especially with fever and redness over the gland, suggests bacterial infection.
- Mealtime swelling: Repeatedly swelling up when you eat and then deflating between meals points toward a duct blockage or stone that may need intervention.
- Chronic or recurrent swelling: Swelling that keeps coming back over months, particularly with dry eyes or dry mouth, warrants testing for autoimmune conditions.
- Firm, fixed lump: A hard mass that does not move freely under the skin is more suspicious than a soft, mobile one.
A lump that has been present and unchanged for years is less worrisome than one that has appeared recently and is growing, but even long-standing lumps deserve evaluation if they have never been formally assessed. Pleomorphic adenomas, while benign, can undergo malignant transformation if left in place for decades, which is one reason surgeons typically recommend removal even when the initial diagnosis is benign.