Sales of VR headsets rose more than 70% last year from 2020, according to International Data Corp., to 7.9 million units. Demand is driven in part by rising hype around the metaverse, a term proponents use to describe a future 3-D version of the internet, comprising virtual worlds where people will get together to work, learn and play.

With interest in the devices growing, so is their reputation for being a source of pain and embarrassment.

When

Nintendo Co.

’s Wii made its debut in the mid-2000s, people hurt themselves using its motion-sensitive controllers. With VR headsets, as initial users found, the risk of getting tripped up is greater, because the devices completely cut off the real world.

Lauren Murray was sympathetic the first time her husband, Taylor Murray, cut his right hand while punching his way through a VR boxing match, splattering blood on the wood floor and blinds in the living room of their Gainesville, Fla., home. But when he broke a glass vase a few weeks later while playing virtual tennis, she no longer saw VR as a practical way for him to work out.

“Why don’t you go to the gym like a normal person?” Ms. Murray, 36, recalled asking him.

Mr. Murray said he bought a new vase and has since cleared out the space where he uses the headset. Causing more damage seems inevitable. “I’m sure I’ll make the same mistake again,” he said.

Last spring, 12-year-old Landon Woodward of Rockwood, Mich., slammed his right hand onto a desk while playing the VR game “Gorilla Tag.” The nail on his middle finger turned black and eventually fell off. He was attempting to tag an opponent in a seemingly vast jungle, while in the real world he only had a 5-by-6-foot patch of open space in his brother’s bedroom.

His father, Matt Woodward, said he has since set up a VR game room for Landon, lined with pillows.

James McLay, 30, of Falkirk, Scotland, bought a mat to stand on so he can feel the area where it is safe for him to play in VR. He did this after an incident in which his body slowly drifted in his girlfriend’s living room as he played the sword-fighting game “Until You Fall.” Having lost track of his location, he attempted to hit an enemy, which resulted in swinging his hand with full force into the metal frame of a nearby shelf. For a week, he was unable to bend a finger on his right hand, which now has a permanent bump, he said.

Mr. McLay said he is more careful with the help of his safety mat.

“I know what to avoid, so I’m not going to end up hitting a wall or anything anymore—or like punching my TV, which has happened” he said.

A Reddit group called VRtoER, started in 2019, has around 80,000 members.

Jay Kim, an associate professor of Environmental and Occupational Health at Oregon State University who has studied VR injuries, said users should take frequent breaks to avoid harmful outcomes such as “gorilla arm syndrome,” a pain caused by keeping one’s arms raised for prolonged periods.

VR headsets commonly come with safety instructions and typically display a grid when a person gets close to the edges of the recommended space surrounding their setup.

Facebook

parent Meta Platforms Inc. recently upgraded the grid system for its Quest 2 headset, called Guardian, so users can receive an alert when a person, pet or object is approaching.

“We’re happy people are enjoying their Quest headsets, but safety comes first,” a spokeswoman for Meta said. A Sony Group Corp. spokeswoman referred to a video with safety tips for using its PlayStation VR headset, such as clearing out furniture, creating a buffer zone and staying seated.

Last spring, Jake Masters of Charlotte, N.C., was in a virtual Roman coliseum fighting a tiger, but in the real world, he was fighting the air. He ended up dislocating his right shoulder and needed months of physical therapy.

“Not having tactile interaction allowed me to overextend it,” said the 29-year-old, who seven years earlier hurt the same shoulder during an actual boxing match. “I wasn’t supposed to do real boxing after the first injury, so I figured I can play games.”

Mr. Masters has resumed playing in VR, but only while sitting down. He plans to revisit the virtual coliseum where he injured himself once he fully recovers. “Next time I’ll just let the tiger eat me,” he said.

James Buckingham of Bedford, England, said he once accidentally struck a girlfriend in the head while playing “Beat Saber,” a VR game that involves striking moving neon blocks with laser swords, or sidestepping or ducking to avoid them, to the tempo of popular songs.

“I heard this shriek and the crumble of someone hitting the floor,” said Mr. Buckingham, 44. “I was terrified and threw off the headset immediately, and bless her, she’s laughing.” He said the incident had nothing to do with their subsequent breakup.

A VR mishap caught on camera led to a small amount of fame and a fortune for Dean Cacioppo of the New Orleans area. A family member recorded him diving headfirst into a 75-inch flat-screen television two years ago while playing a demo that came with his headset.

In the VR demo, Mr. Cacioppo was standing at the edge of a plank atop a skyscraper. All of a sudden, he lunged forward—in real life—because he wanted to prove he was fearless.

“I just decided to jump off knowing I wasn’t literally jumping off of a building,” said the 48-year old. “I wanted to be the strong dad.”

Mr. Cacioppo said he was fortunate to walk away from the incident with only a bruised ego. “I was fine,” he said, “but the TV was messed up pretty bad.”

Two of his daughters posted the seven-second video of the crash to TikTok and

Twitter,

where it went viral. Mr. Cacioppo sold partial rights to use it to a marketing agency in Australia for $300. That helped pay for a new TV, which was around $2,000.

Write to Sarah E. Needleman at sarah.needleman@wsj.com and Salvador Rodriguez at salvador.rodriguez@wsj.com