For about a decade, Mark Hoffman had a leaking ear. Every morning his pillow was drenched in a mysterious clear fluid. And every 30 minutes, the fluid would completely soak a cotton ball . “It was dripping every 10 seconds,” he told the Indianapolis Star. “I used over 5,000 cotton balls in my ear.”

The issue remained a mystery for 10 years. “Nobody had any idea what this was,” Hoffman said in an interview with Today. But a neurotologist at Indiana University Health finally fixed Hoffman’s leak. Turns out a piece of the 53-year-old's skull had worn away, and cerebrospinal fluid was draining from his brain into his ear canal.

Believe it or not, this issue seems to be on the rise in the general population—and it’s crucial to get a cerebrospinal fluid leak corrected ASAP. To find out more about the scary sounding condition, we spoke with George Wanna, MD, site chair of the department of otolaryngology-head and neck surgery at the New York Eye and Ear Infirmary of Mount Sinai and Mount Sinai Beth Israel in New York City.

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How does a cerebrospinal fluid leak happen?

The brain sits on top of the ear inside the skull, and there’s a bone shelf separating the two. A “leak” occurs when there’s a hole in that bone, says Dr. Wanna. People will visit an ENT either because they have strange fluid in the ear, or they’re swallowing it and experiencing a funny taste in their throat.

The hole can occur as the result of trauma, infection, a past surgical issue, or spontaneously. But doctors are seeing an uptick in spontaneous leaks as obesity rates climb. “Research shows there’s a higher incidence of cerebrospinal fluid leaks in those who are obese," Dr. Wanna says. "Pressure inside the skull increases, and the brain begins to pulsate on the bone, which eventually breaks and springs a leak.”

How dangerous is it?

Although Hoffman went a decade before getting his brain fluid leak fixed, you should really try to get this issue diagnosed and fixed right away. “There are some very serious complications that can develop with a fluid leak, like meningitis or a brain abscess,” Dr. Wanna says. “Then it can require urgent surgery.”

If you’re experiencing symptoms of a leak, like unexplained fluid in your ear, see an ear, nose, and throat physician (ENT) for prompt diagnosis. Look out for liquid that appears “very clear and thin,” says Dr. Wanna.

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How do you fix a leak?

Dr. Wanna used to see around 20 to 25 leak cases per year when he worked in the South, and has seen a couple at his current post in New York City this year. “The spontaneous leaks are becoming more and more common,” he says.

Depending on the location of the bone shelf’s hole, you might need different kinds of surgery. Hoffman’s operation took around three hours to complete, but it varies. “With research, we’ve found the most successful procedure involves both a neurosurgeon and an ENT,” says Wanna. “In those cases, you patch the hole both above and below the ear.”

Bottom line: don’t wait

The important takeaway is that a cerebrospinal leak is quite fixable, but should be addressed promptly. If you ever seem to “spring a leak,” call your doc as soon as you can.