Salivary gland disorders: causes and treatment

The major salivary glands are the parotids, which lie in front of and below the ears, the submandibular glands beneath the jaw, and the sublingual glands on the floor of the mouth. Cancer Research UK adds that there are more than 600 minor glands in the lining of the mouth and throat.

NHS Greater Glasgow and Clyde guidance for GPs sorts problems into tumour, infection and duct causes. The distinction is practical, because each has a different pattern of swelling and a different next step.

Comparing the two sides of the face and mouth is the first thing a clinician does. The guidance notes that glands can become more obvious with age or after significant weight loss, so a difference in appearance does not always mean disease.

Salivary stones are small stones that can block the flow of saliva. The NHS says most form below the tongue, are white and hard, and are usually about the size of a pea. The typical sign is dull pain or swelling in the mouth that comes and goes, and sometimes flares at mealtimes.

The GP guidance says duct stones impede salivary flow, causing intermittent swelling and discomfort in the gland on eating, and can raise the risk of infection in the gland. The NHS says intense pain at mealtimes lasting 1 to 2 hours can mean a gland is completely blocked.

A separate guide covers stones in more detail, including home measures and what a GP or hospital team can do.

Infection can be viral or bacterial. The Glasgow guidance says viral causes, for example mumps, are more common in younger patients. In older people bacterial causes are more common, often follow a period of dehydration, and can reflect significant frailty.

The NHS describes mumps as painful swelling of the cheeks and neck that gets worse over a few days, which may cause earache or make it harder to chew, swallow or speak. It usually gets better within 2 weeks. A GP will arrange a test to confirm it, and the NHS advises speaking to the GP surgery before going in, as mumps spreads easily.

When the whole gland is swollen, the GP guidance suggests warm compresses, gland massage and sialogogues, such as lemon juice, which encourage saliva flow, with an antibiotic course prescribed where bacterial infection is suspected.

Sjögren's syndrome is an autoimmune condition in which the immune system attacks the glands that make fluids. The NHS lists dry eyes and mouth as typical, along with swollen glands in the cheeks, neck and under the jaw, which are the salivary glands, and an unpleasant taste in the mouth.

Tests described by the NHS include blood tests, eye tests, a spit test where you dribble into a container for 5 minutes to measure saliva produced, an X-ray of the salivary glands to see if they are blocked, and sometimes a lip biopsy. Doctors can prescribe medicines to keep the eyes and mouth wet or help glands produce more saliva, and to ease pain and swelling if a gland is infected.

Pharmacists can help with eye drops, mouth gel and mouthwash. Persistent dry mouth with gland swelling therefore deserves a medical review rather than being put down to ageing.

A discrete, firm lump suggests a tumour. The Glasgow guidance says most of these lesions are benign: in the parotid gland, 80% of tumours are benign, and in the submandibular gland, 50%. Cancer Research UK says that 3 in 4 parotid tumours are benign.

Cancer, though rare, is the reason lumps are not ignored. Cancer Research UK lists a painless lump in the jaw, cheek, mouth or neck, facial numbness, drooping of one side of the face, problems swallowing and difficulty opening the mouth as possible signs of salivary gland cancer.

The most common benign tumour, a pleomorphic adenoma, is usually slow growing, and surgery is typically suggested because a small risk of cancer exists within it. The full picture of cancer is covered in a separate guide.

See a GP if a stone has not gone away by itself, or if there are signs of infection such as pain, redness or pus, and a high temperature or feeling hot, cold or shivery, according to the NHS. A persistent neck lump of more than 3 weeks should be referred urgently to ENT on suspicion of cancer, and a persistent floor-of-mouth lesion for more than 3 weeks to the maxillofacial department, says the Glasgow guidance.

For a suspected duct stone, referral to ENT is routine. If mouth, face or neck swelling affects breathing or swallowing, or comes with a high fever and spreading redness, seek urgent care through NHS 111 or A&E.