Mahjong can maybe cause a little heartburn, if you snack too much between games, or, God forbid, some palpitations, if the game is taking so long you’re worried you’ll be late for the podiatrist. But seizures?

This month’s Hong Kong Medical Journal claims the game can cause “mahjong epilepsy.”

The new illness has been documented among 23 people in Hong Kong and Taiwan who suffered seizures only when playing the tile-clicking game. At least one player’s symptoms disappeared completely when he quit the game, and flared up again when he resumed. All of which sounds downright surreal to anyone who grew up thinking of mahjong as a game played by mothers and grandmothers — usually Jewish ones — in between bites of bundt cake and whispers about who had cancer.

The truth is, mahjong was and is a favorite among Jewish ladies, for historic reasons I’ll get to in a second. It’s also played by millions of people in Asia, and Asians in America, and, increasingly, by folks beyond those ethnic groups. The number of players has grown by 25% to 30% in the past 10 years, the president of the National Mah Jongg League, Ruth Unger, said, “and many of them have last names we here in the office can’t pronounce, which is extremely gratifying.”

So it’s not your grandma’s mahjong anymore, and maybe that’s what’s bringing on the seizures — a new competitive spirit, or bigger bets. But even if the game is getting cut-throat in some circles, most players still seem to appreciate it for being something else entirely: glue.

“It’s kind of a bonding thing,” a spokeswoman for the Museum of Chinese in the Americas, Amanda Heng, said. “It’s like an excuse to eat and make merry and have fun on a Saturday night.” Come the Asian New Year, she added, the games can go on for days — as can the eating.

“You know what the best part about mahjong is? It’s Wednesdays I have something to do,” a Florida player, Rose Freed, said. Like many mahjong vets, Ms. Freed insists she was “born knowing” the game and spent her young married years in its thrall.

“That was some mahjong game,” she said. “In the winter we’d go to Nathan’s for hot dogs, or Dubrow’s Cafeteria at 1 or 2 in the morning afterward to eat, and I had to be sooo sweet to the kids the next day, because if I yelled, my husband would think I’d been out too late.” What she loved about those nights, Ms. Freed said, “wasn’t the game. It was the gals.”

Ms. Unger, president of the New York-based league for 26 years, feels exactly the same. “You’re mixing the tiles and you talk and you talk and these people become your network, your support group — everything you need.”

You’re even doing good while having fun. How so?

Mahjong first took America by storm in the ’20s after it was brought over by a Standard Oil employee who’d played it in Shanghai, Joseph Babcock. The game became so popular, Edie Cantor was singing “Since Ma is Playing Mah Jong” even as Midwestern meatpackers were shipping cattle bones to China to meet the demand for more tiles.

It was a classy game, and back then, Ms. Unger said, “my sense is that the middle class and affluent Jewish people wanted to be just like WASPs.” Playing mahjong did the trick.

Unlike other WASPy games such as golf, however, mahjong lacked standardized rules. One well-off Jewish woman changed this by founding the National Mah Jongg League in 1937. It became the mahjong authority, issuing the official American rules, colloquially known as “Jewish rules.” It also pledged to devote all its profits to charity — something the league still does.

“We supported a pediatric wing at the Joe DiMaggio Hospital in Florida, and a wing at the Nassau University Medical Center. Now they need a new biopsy table which costs over $100,000, which we plan on supporting,” Ms. Unger said. Those are just a few of the projects paid for by League memberships, which cost $6.50 or $7.50 a year.

Clearly, a lot of people are still sending in their dues and clicking their tiles, a sound that, for me at least, will forever conjure up leisure. Not seizures.