Ohio State’s head football coach Urban Meyer has grabbed his head in pain enough this season that the speculation has started about his health.

Meyer dropped to his knees on the sidelines of Saturday’s game against Indiana due to a massive headache.

What’s causing it?

Since his days as an assistant coach at Notre Dame, Meyer has suffered from an arachnoid cyst.

After years of suffering, Meyer underwent a procedure to treat the issue in 2014, where he had fluid removed to relieve some pressure.

It sounds dangerous, but the fact is millions of Americans suffer from it and it’s non life-threatening.

But Meyer knows the image of the second highest paid college football coach in the country buckled over in pain is a bad one, and admits that it’s a situation that is being watched closely.

“I’ve been dealing with that cyst for many years,” Meyer said. “We had surgery several years ago. When it does take place, they give me some medicine. I feel fine now. It’s something we have to monitor.”

So what, exactly, is an arachnoid cyst?

“It’s a benign cyst on the membrane tissue that covers the brain,” says Dr. Robert Brodner, a board-certified neurosurgeon at Good Samaritan Medical Center in West Palm Beach. “They occur congenitally in about 5 to 6 percent of the population — with the vast majority being asymptomatic.”

In other words, most people who have one are never even aware of it.

However, sometimes people do suffer symptoms (as was described in Sports Illustrated of Meyer experiencing two episodes of blinding head pain while on the sidelines during games in 1998 and 2003). When that happens, it’s because, says Brodner, “Over time, the cyst can slowly, progressively enlarge as it imbibes spinal fluid. The enlargement can then exert pressure on the part of the brain in closest proximity to the cyst.”

The associated symptoms depend on which part of the brain is being pressured. But, Brodner said, the most common ones are “headaches, nausea, vomiting and gait disturbance.”

From the 2009 book, Urban’s Way:

Since his days when he blacked out and nearly fell while on the sidelines as an assistant at Notre Dame, Meyer had tried to learn how to better control his emotions. It turned out to be an arachnoid cyst on his brain, benign, but it also caused severe migraines when aggravated by emotional stress. The doctors told Meyer to “cool it with the screaming and yelling”, which he did until he became a head coach at Utah. During a game against Oregon, in a tense moment or the fourth quarter, he almost passed out. Doctors helped him pinpoint those emotional outbursts – usually, in the fourth quarter – and he began to alter his behavior pattern.”

It was during the 4th quarter last Saturday when the massive headache hit Meyer yet again.

Has the coach thought about having another surgery?

“No,” Meyer said today. “Just get by with what we’re doing.”

That’s similar to what Meyer said four years ago, after the issue came up.

“I’ve had it for several years. It’s a cyst, an arachnoid cyst. It surfaced a couple of times, once in ’98 and once in ’04 and a couple of other times. It’s just something you’ve got to manage.”

Let’s hope it can be managed as the Buckeyes unblemished season continues.