A ranula is a soft, dome-shaped, often bluish swelling that appears on the floor of the mouth, under the tongue. It forms when one of the sublingual saliva glands is damaged or blocked and saliva leaks out and pools under the lining. It is usually painless and harmless, but it can grow large enough to push the tongue up, interfere with speech or eating, and it has a strong tendency to come back unless the right treatment is chosen. The single most important fact about ranulas is this: removing the affected gland gives by far the lowest recurrence rate.
This guide explains what a ranula is, why it happens, how it is treated, and what the evidence says about keeping it from returning.
Key takeaways
- A ranula is a saliva-filled swelling under the tongue, caused by a leaking or blocked sublingual gland.
- It is a pseudocyst, meaning it has no true cyst lining; it is a pool of escaped saliva.
- Most are painless but can grow and affect speech, chewing, and swallowing.
- Removing the sublingual gland has the lowest recurrence, often around 1 to 4 percent. Simply draining or unroofing it returns in roughly half of cases or more.
- A "plunging" ranula extends down into the neck and needs specialist assessment.
What a ranula actually is
The name comes from the Latin for little frog, because a large one can resemble a frog's translucent throat sac. Saliva glands sit under the tongue and constantly produce saliva. If the duct of a sublingual gland is blocked or the gland is bruised, for example after minor trauma, saliva escapes into the surrounding tissue rather than flowing into the mouth. The body walls it off, and a soft fluid-filled swelling builds up. Because there is no true membrane around it, doctors call it a pseudocyst.
There are two main types. An oral ranula stays in the floor of the mouth as a visible bluish dome. A plunging ranula tracks downward through the muscle and presents as a soft lump in the neck, sometimes with little or nothing visible in the mouth. The plunging type needs imaging and specialist input.
What causes a ranula
Most ranulas are linked to minor damage or blockage of a sublingual gland. Contributing factors can include:
- Minor trauma to the floor of the mouth, including some dental procedures or a knock to the area
- A blocked salivary duct
- In some people, no clear cause is ever found
They are most common in children and young adults. Unlike a small mucocele on the lip, which often bursts and resolves on its own, a ranula rarely settles without treatment because of the volume of saliva the sublingual gland produces.
How a ranula is diagnosed
An oral ranula is usually diagnosed by its appearance: a soft, bluish, fluctuant swelling under the tongue. A plunging ranula, or a swelling that is not clearly a ranula, may need an ultrasound or MRI to map its extent and rule out other causes. A dentist or oral surgeon will also check that the lump is not something that needs different management, applying the same caution we describe in assessing unusual patches and lumps.
Treatment options and recurrence
This is where the choice of treatment really matters, because the options differ enormously in how often the ranula comes back.
| Approach | What it involves | Approximate recurrence |
|---|---|---|
| Removing the sublingual gland | Taking out the gland that is leaking, with or without the ranula | Around 1 to 4 percent (lowest) |
| Marsupialisation | Unroofing the swelling so it drains into the mouth | Often 50 percent or higher |
| Simple removal of the ranula only | Excising the pseudocyst but leaving the gland | Around a third or more |
| Drainage alone | Aspirating the fluid | Very high; usually refills |
The pattern is clear. Treatments that leave the sublingual gland in place tend to recur, because the gland keeps producing saliva that can leak again. Removing the gland addresses the source, which is why it is widely regarded as the definitive treatment. Marsupialisation is less invasive and can be a reasonable first step in some cases, especially in children, and packing the cavity afterward can improve its success, but patients should understand the higher chance of it returning.
What recovery is like
Removing a sublingual gland is usually a short procedure done under local or general anaesthetic. Afterward you can expect some swelling and tenderness for a few days, a soft diet for a short period, and careful oral hygiene around the area. The lingual nerve and the submandibular duct sit nearby, so the procedure is best done by a clinician experienced with the floor of the mouth. Losing one sublingual gland does not cause a dry mouth, because the major glands continue to produce most of your saliva.
General cost in Australia
Cost depends on the approach, the anaesthetic, and whether the procedure is done in a clinic or hospital. The figures below are general market ranges, not a quote.
| Service | Typical Australian range | Notes |
|---|---|---|
| Consultation and diagnosis | $80 to $200 | May include imaging referral |
| Marsupialisation | $400 to $1,200 | Less invasive, higher recurrence |
| Sublingual gland removal | $1,500 to $4,500+ | Higher with general anaesthetic or hospital |
The team at Lumi Dental does not list its own prices here. For current options and a written quote, see our current offers or our general dentistry page.
Frequently asked questions
Is a ranula dangerous?
An oral ranula is benign and not cancerous. It is mainly a nuisance that can affect speech and eating if it grows. A plunging ranula in the neck should be assessed by a specialist, but it is still a benign condition.
Will a ranula go away on its own?
Small ones occasionally settle, but most do not, because the sublingual gland keeps producing saliva that refills the swelling. Treatment is usually needed for a lasting result.
Why did my ranula come back after treatment?
Almost always because the sublingual gland was left in place. Draining or unroofing a ranula without removing the gland has a high recurrence rate. Removing the gland gives the lowest chance of return.
Does removing a saliva gland cause dry mouth?
No. You have many saliva glands, including large ones near the jaw. Removing one small sublingual gland does not noticeably reduce overall saliva.
The bottom line
A ranula is a harmless but persistent saliva-filled swelling under the tongue. The key decision is the treatment: anything that leaves the leaking gland behind tends to come back, while removing the gland gives the most reliable result. If you have a soft bluish swelling under your tongue or an unexplained soft lump in your neck, the team at Lumi Dental in Melrose Park can assess it and arrange the right care. See our current offers to book a consultation.
