September 21, 2023
September 20, 2023

Understanding Parotid Gland Functions and Disorders

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Understanding Parotid Gland Functions and Disorders

The parotid gland is a type of salivary gland in your body. A pair of these glands is located in the back of your lower jaw in front of the ears. While you may not give much thought to salivary glands or the jobs they do, they play a significant role in your health. 

Their main job is producing saliva. Saliva is the liquid that not only keeps your mouth from feeling dry, but it also helps break down food for digestion and keeps the amount of bacteria in your mouth under control. 

When things go awry with the parotid glands, it can profoundly impact your health. In this article, we’ll discuss parotid gland anatomy and functions along with conditions like parotitis, parotid gland stones, and parotid tumors. 

Parotid Gland Anatomy and Functions

The parotid glands are the largest salivary glands in the body. They’re located in front of each ear, and their secretions are released into the mouth through a duct near the upper second molar. Each parotid gland has two lobes: the superficial lobe and the deep lobe. The facial nerve runs between the two lobes. The facial nerve is important for facial expressions like smiling, frowning, and blinking.

Parotid gland secretions are made up of enzymes like amylase for digestion and liquids like water and mucus that carry the enzymes and keep your mouth lubricated. Parotid glands produce about 25% of your saliva.

Other major salivary glands include submandibular glands in the lower jaw and sublingual glands under your tongue in addition to hundreds of minor salivary glands. Each gland is made up of lobules and functional structures called acini — these create saliva and drain secretions into your mouth through passageways called ducts. The parotid duct, also called Stensen’s duct, empties near your upper molar teeth.

Saliva helps with oral hygiene and mouth health in a few ways. First, saliva helps wash away food particles and keeps bacteria from sticking to your gums and teeth. This helps prevent the growth of plaque, which can cause tooth decay and gum disease. Second, saliva contains antimicrobial agents that can kill bacteria or inhibit its growth. Finally, saliva helps your body balance the pH of your mouth to maintain healthy levels so bacteria can’t thrive.

What Causes Parotid Gland Inflammation?

When your parotid gland swells it’s called parotitis. Sometimes this inflammation is caused by an infection (bacterial or viral). Symptoms of parotitis include pain, enlargement, and tenderness near the gland. You may also notice that nearby lymph nodes are swollen.

In general, warm compresses may help relieve discomfort but specific treatment of parotitis depends on the underlying cause. Note: If swelling persists, see your dentist or healthcare provider. 


Mumps and influenza are two viruses known for infecting the major salivary glands, including the parotid gland, causing the sides of the face to swell. There is no cure for mumps while influenza may be treated with antiviral drugs. General treatment for viral parotitis includes rest, hydration, and fluids. During the 10-25 day course of infection, your doctor will let you know what pain medication is safe to use.


A blocked salivary duct can lead to a bacterial infection of the gland. Usually, this impacts only one gland so the pain and swelling will be on one side of the face. However, it can progress to a systemic infection if left untreated. If your doctor suspects a bacterial infection, they’ll likely prescribe antibiotics to treat it. 

You’ll also need testing to find out what caused the blockage in the first place. To diagnose and treat salivary gland issues — such as stones, strictures (narrowing), inflammation, and tumors — your doctor may recommend a sialendoscopy. Imaging tests like a computed tomography (CT) scan, ultrasound, and magnetic resonance imaging (MRI) also play a role in detecting abnormalities of the parotid gland.

What Are the Causes and Symptoms of a Blocked Parotid Salivary Gland?

Parotid: confused woman holding her face

A blocked parotid gland is usually caused by an obstructed duct. The blockage keeps saliva from flowing freely from the gland to the mouth. As mentioned, this could be caused by infection. It could also be caused by several other conditions. 

Salivary stones (Sialolithasis): Calcium deposits can cause hard stones to form within the duct. This is the most common cause of blockages.

Mucus plugs: Typically, salivary mucus is serous (watery and thin). As we age, mucus can become more viscous (thick and sticky). Other causes of mucus plugs include dehydration and dry mouth resulting from the side effects of a medication. 

Trauma and structural abnormalities: Injuries affecting the mouth, head, or neck as well as congenital structural abnormalities can cause strictures or narrowing of salivary ducts. 

Tumors: Both cancerous and non-cancerous salivary gland tumors can form in the Stensen’s duct causing blockages.

How Serious Is a Parotid Tumor?

Parotid gland tumors can be cancerous or non-cancerous. Any salivary gland tumor large enough to impact the function of the parotid gland or the flow of saliva can cause significant health problems whether it’s cancerous or not. 

About 6 people in 100,000 are diagnosed with a parotid tumor each year in the United States. Around 75% of parotid tumors are benign (not cancerous), while 25% are malignant (cancerous). The main difference is that cancerous (malignant) tumors can spread (metastasize) to other areas of the body if left untreated or not caught early.

The incidence of parotid cancer is higher in men than in women, and it’s more common in people over the age of 50. The most common type of parotid cancer is mucoepidermoid carcinoma, which accounts for about 40% of cases. 

Other types of parotid cancer include polymorphous low-grade carcinoma, pleomorphic adenoma, adenoid cystic carcinoma, squamous cell carcinoma, and adenocarcinoma

What Are the Causes or Risk Factors for Parotid Cancer? 

Salivary gland cancer is a rare cancer, so there’s still much that is unknown about its causes. However, according to the Journal of Epidemiology, some studies have suggested that the following factors might increase the risk of developing salivary gland cancer:

  • Exposure to radiation: Radiation exposure, such as from radiation therapy for head and neck cancer, can increase the risk of salivary gland cancer.
  • Workplace exposures: Exposure to certain substances in the workplace, such as nickel alloy dust, silica dust, asbestos, and rubber products, may increase the risk of salivary gland cancer.
  • Tobacco use: Smoking and chewing tobacco have been linked to an increased risk of all oral and head and neck cancers.
  • Alcohol consumption: Heavy alcohol consumption may increase the risk of oral cancers including parotid cancer.
  • Exposure to certain viruses: Exposure to certain viruses, such as HIV, Epstein-Barr virus, and possibly human papillomavirus (HPV), may also increase the risk of parotid salivary gland cancer.

These are just some of the possible risk factors for salivary gland cancer. Not everyone who’s exposed to these risk factors will get cancer, and many people who develop salivary gland cancer have no known risk factors. 

What Does a Parotid Tumor Feel Like?

The parotid glands can be felt at the anterior (front) and inferior (under) the ear toward the surface of the cheek. Parotid tumors might first show up as swelling near the cheekbone (zygomatic arch) or jaw, close to the masseter muscles that help you chew. 

Some parotid tumors are slow-growing, painless masses often in the lower part or tail of the parotid gland. Parotid cancer tumors sometimes go through a phase of accelerated growth, which can be a warning sign that the tumor has become more aggressive. They can feel like a firm or hard lump or swelling on or near the jaw, around the ear, or in the mouth. 

How Are Parotid Tumors Diagnosed?

To diagnose salivary gland cancer, doctors will perform a physical exam and health history, as well as diagnostic imaging tests like MRI, CT scan, and PET scan. These tests can create detailed images of the inside of the body, which can help doctors see if there’s a tumor or other abnormality. 

  • MRI uses strong magnetic fields and radio waves to produce detailed images of the inside of the body.
  • A CT scan is an imaging exam that uses X-ray technology to produce images of the inside of the body. A CT scan can show detailed images of any part of the body, including bones, muscles, organs, and blood vessels.
  • PET scan uses a radioactive tracer to produce images of the tissues that are actively using glucose (sugar).

A definite answer requires follow-up testing. During a biopsy, your doctor will take small tissue samples. A pathologist then examines the cells for the presence of cancer.

Two main types of biopsies are used to diagnose salivary gland cancer: fine needle aspiration (FNA) biopsy and incisional biopsy. The mass can be removed and checked for signs of cancer if cancer diagnosis can’t be ruled out from a FNA biopsy or incisional biopsy. Your doctor can then offer a treatment plan based on the findings.

Do Parotid Tumors Need to Be Removed?

Cancer treatment may include surgery. If the tumor presses against the facial nerve, a procedure known as parotidectomy (removal of part or all of the parotid gland) is often recommended. 

Often, surgeons trained in ear, nose, and throat (ENT) surgery or head and neck surgery are brought in. That’s because it may be necessary to consider nearby structures, such as the external carotid artery, retromandibular vein, gland deep lobe, and mandible during the procedure. 

Even though benign tumors are not cancerous, they may still grow and cause complications or cosmetic concerns. As with every medical decision you make, the risk should be weighed against the benefits.

Take Action When It Comes to Cancer Screenings

Parotid: girl kissing and hugging her father

To determine the cause and proper treatment of any swelling of the parotid gland or other salivary glands, a healthcare professional must evaluate them. Understanding the parotid gland and its importance to overall health can help you become more aware and seek medical advice sooner as early detection is key to better outcomes. 

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