Today in viral videos, the Internet is having a collective freak-out over footage of a worm-like shape emerging from beneath a man’s tongue. The cell-phone video (below—watch at your own risk!) looks a bit like something out of an Alien movie. But it’s actually depicting a somewhat common medical phenomenon, albeit a pretty extreme case.

This phenomenon, as YouTube user Brandon Douglas wrote, is known as a salivary stone. According to Douglas’ comments on Reddit, he had been experiencing pain for about five days. A doctor told him there was a blockage, and possibly a stone, in his sublingual (under-the-tongue) salivary gland.  

When Douglas, an American stationed at a Navy base in Bahrain, felt the blockage pushing its way out, he grabbed his phone and started recording. “I woke up in the morning and it felt very hard,” he wrote. “I went to the bathroom and flexed my tongue and a stone came out!”

That stone was several centimeters long, and left a noticeable hole in Douglas’ mouth after he pulled it out entirely. But what the heck was it, and could it happen to any of us? Here’s what we know.

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Intro to salivary stones

Salivary stones, also known as salivary duct stones or sialolithiasis, are made up of calcium and other minerals naturally found in saliva. When saliva ducts—tiny openings in your mouth that produce saliva—become blocked, those minerals can build up and harden beneath the surface of the skin.

This can cause pain and swelling, especially when saliva flow is stimulated. On Reddit, Douglas wrote that the stone was “extremely irritating” for several days. “Whenever I would eat there would be nowhere for saliva on that side to go so the gland would just swell up and be really sore.”

But it’s not always painful or obvious, says Mary Gadbois, DDS, a dentist in private practice in Columbus, Missouri. “A lot of times people aren’t aware of it until it starts to displace their tongue,” she says. “We had one patient who came in not because his mouth hurt, but because his dentures didn’t fit anymore.”

Salivary stones can form when a duct is damaged due to some type of trauma, she says, or when saliva flow is slowed. People with dry mouth—because of certain medications, dehydration, or other medical conditions—are much more prone to them.

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What should you do if you think you have one?

Most salivary stones are small, and they often can be coaxed out out on their own by stimulating salivary flow. Dr. Gadbois recommends drinking lots of water and sucking on tart lemon candies throughout the day.

“That can create this river behind the stone and push it out,” she says, “kind of like how you can sometimes flush out kidney stones by drinking a lot of water.”

Your doctor or dentist may encourage you to try this for a few days, Dr. Gadbois adds. If it doesn’t come out on its own—or if you’re in a lot of pain—you may need surgery.

“We’ll get them numb and make a small incision and cut it out,” she says. “Normally we don’t even have to put a stitch in and it heals fine on its own.”

Doctors often put patients to sleep to do this surgery, Dr. Gadbois says, while dentists, who are more accustomed to doing oral surgery while patients are awake, tend to use local anesthesia.

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Should you try to pull it out?

Dr. Gadbois doesn’t recommend using tweezers or anything sharp to remove a stone, but says that gentle massaging around the duct can sometimes help jumpstart the removal process.

If it doesn’t come out easily, however, see a professional. “If you can get to a dentist, it’s not expensive or complicated to have them numb you and extract it quickly,” she says. “That’s probably a lot nicer for the patient, versus trying to do it at home.”

Once it’s out, says Dr. Gadbois, talk to your doctor or dentist about what you can do to prevent other salivary stones in the future. That may involve staying well hydrated, or taking a closer look at your medications to see if any may be cutting off your saliva supply.

Except in cases of infection or extensive surgeries, people usually recover from salivary stones quickly and fully. When asked on Reddit what’s next for him, Douglas responded with relief: “Just ate an entire pizza without any pain. I regret nothing.”