What are the salivary glands and what do they do?

Types of salivary gland 

People typically have three pairsTrusted Source of major salivary glands and hundreds of minor salivary glands. The major salivary glands are the largest of the salivary glands and produce most of the saliva in the mouth.

Below are the three typesTrusted Source of major salivary glands:

• Parotid glands: These are the largest of the salivary glands. They are just in front of and below the ears. A person has one parotid gland on each side of their face.
• Submandibular glands: These are the second-largest salivary glands. They are below a person’s jaw.
• Sublingual glands: This gland is below the tongue. Instead of having one main duct, these glands contain a series of short ducts. They project saliva directly onto the floor of a person’s mouth.

The major salivary glands produce around 92–95%Trusted Source of a person’s saliva. The minor salivary glands produce the remainder of a person’s saliva.

A person has about 600–1,000 minor salivary glands. They are in almost every part of the mouth, but most commonly in the:

• lips
• lining of the cheeks
• tongue
• palate

What do the salivary glands do? 

The salivary glands produceTrusted Source saliva and secrete it into the mouth.

Saliva plays a role in helping a person chew and swallow food by making it moist. It also lubricates the surfaces within the mouth, which can help facilitate speech.

Saliva also contains enzymes that help a person digest certain substances in their food.

For example, saliva containsTrusted Source the enzyme amylase, which helps break down starches into sugars. This makes it easier for the body to absorb the starches.

Saliva also contains the enzyme lipase. This enzyme helpsTrusted Source break down triglycerides, which are a type of dietary fat, into glycerol and free fatty acids. This makes it easierTrusted Source for the body to absorb these fats.

Additionally, saliva plays a role in helping protect against infection. This is because it contains compounds with antimicrobial properties, such asTrusted Source:

• lysozymes, which are a type of enzyme
• hydrogen peroxide
• lactoferrin, which is a type of protein

These compounds kill germs and help keep the mouth clean. Disruptions in saliva secretion can increase a person’s risk of developing certain conditions, such as:

• tooth decay
• gum disease
• candidiasis, or yeast infections
• respiratory tract infections

What conditions affect the salivary glands? 

Below are five examples of conditions that can affect the salivary glands.

Salivary gland stones

Salivary gland stones are small stones that form in a person’s salivary glands. These stones can block the flow of saliva out of the glands.

According to the United Kingdom’s National Health Service, they are not typically serious, and a person may be able to remove them on their own by:

• drinking plenty of water
• gently massaging around the salivary gland stone
• sucking on a lemon or lemon drops

Most salivary gland stones form below the tongue. In some cases, a person may be able to see them.

Symptoms of salivary gland stones include:

• swelling in the mouth, face, or under the jaw
• a dull pain in the mouth that comes and goes
• an infection around the stone

If a person experiences intense pain when eating, this may mean that the stone is completely blocking a salivary gland.

Salivary gland infections

If an obstruction blocks a duct in a salivary gland, it can causeTrusted Source saliva to pool in the duct. This can cause a salivary gland infection to develop.

Symptoms of a salivary gland infection includeTrusted Source:

• swelling of the salivary gland
• malaise
• fever
• headache
• muscle aches and pains

If a person has an infection of the lymph nodes due to a cold or sore throat, it can cause them to develop a secondary infection of the salivary glands. This may happen as the saliva becomes thick and stuck behind the gland.

Salivary gland cancer

Salivary gland cancer is a rare diseaseTrusted Source. It occurs when cancer cells form in the salivary glands.

If a person has salivary gland cancer, they may not experience any symptoms. A healthcare professional may discover this type of cancer during a regular dental exam or a physical exam.

However, some possible symptoms of salivary gland cancer include:

• a lump that may be painless in the:
  • cheek
  • inside the mouth
  • jaw
  • lip
  • ear
• difficulty swallowing
• fluid draining from the ear
• difficulty opening the mouth wide
• pain in the face that does not go away
• numbness or weakness in the face

Benign (noncancerous) masses can also form in the salivary glands.

A person should speak with a doctor if they discover any lumps in their mouth, face, head, or neck.

Mumps

Mumps is a contagious viral infection that causesTrusted Source a person to develop puffy cheeks and a swollen jaw due to swelling in the salivary glands.

Other symptoms of mumps include:

• fatigue
• fever
• aching muscles
• headaches
• loss of appetite

The Centers for Disease Control and Prevention (CDC)Trusted Source recommends that people receive the MMR vaccine to help reduce the risk of experiencing mumps.

Sjögren’s syndrome

Sjögren’s syndrome is a chronic autoimmune disorder that attacksTrusted Source certain glands. This includes the lacrimal glands, which make tears, and the salivary glands. The condition predominantly affects females.

Common symptoms of Sjögren’s syndrome include:

• dry mouth
• dry eyes
• muscle pain
• fatigue
• joint pain

It can also damage the:

• kidneys
• lungs
• nervous system

When to contact a doctor 

The following symptomsTrusted Source may indicate a problem with a person’s salivary glands:

• dry mouth
• bad taste in the mouth
• difficulty opening the mouth
• swelling in the face or neck
• swelling under the tongue
• numbness or weakness of the face
• pain in the face of mouth
• a lump in the:
  • mouth
  • cheek
  • jaw
  • lip
  • ear
• fluid that drains from the ear

If a person experiences any of these symptoms, they should consider speaking with a doctor who can help identify any underlying causes.

Summary

The salivary glands produce saliva and secrete it into the mouth. Saliva helps a person chew and swallow their food. It also lubricates surfaces in the mouth to help facilitate speech.

Saliva contains enzymes that help a person digest certain substances, such as starches and fats, in their food. It can also help protect the body against infection.

There are three pairs of major salivary glands and hundreds of minor salivary glands. The main salivary glands are the parotid glands, the submandibular glands, and the sublingual glands.

Conditions that affect the salivary glands include salivary gland stones, infections, cancer, mumps, and Sjögren’s syndrome. People should contact a healthcare professional if they think they are experiencing any problems with their salivary glands.