Staying in and playing video games may not be as safe as it sounds. In a new case study, physicians describe how an unnamed patient was admitted and treated for a potentially life-threatening condition after four consecutive days of intense gaming. Aside from confirming the long-held belief that computer and video entertainment carry their own risks, the findings may inspire new public health recommendations.

The patient, whom the case study describes as a 31-year-old Caucasian male employed as an exterior painter, came to the hospital with pain and swelling in his left leg. According to the study authors, the patient told doctors that he had been playing video games for almost eight hours a day for four consecutive days. “He was on holiday and spent each day sitting on his bed with his legs outstretched playing PlayStation games,” they wrote. “He would play for seven to eight hours continuously without getting off the bed.”

“On the second day, he developed left leg pain with associated calf swelling and erythema, but despite increasing discomfort, continued to play video games until presenting two days later,” they continued. “There was no history of trauma to his left leg, recent surgery, or previous venous thrombosis.”

The unnamed 31-year-old was eventually diagnosed with deep vein thrombosis — a serious condition characterized by one or more blood clots in the deep veins of the leg. According to the Mayo Clinic, the condition can be brought on by prolonged periods of sitting and inactivity. If left untreated, the deep vein thrombosis is potentially fatal, as a dislodged clot may travel through the body and block blood flow to the lungs.

Though unusual, the case is not without precedent. In 2011, ABC News reported the sad story of 20-year-old Chris Staniforth, who died of pulmonary embolism after he spent 12 consecutive hours on his computer. The tragedy caused several experts to call for public health advisories emphasizing the importance of frequent breaks during prolonged periods of gaming.

"We're seeing now that one of the biggest recreational activities is playing video games instead of being outside and being physically active," Phil Ragno, director of cardiovascular health and wellness at Winthrop University Hospital in Mineola, N.Y., told reporters. "Try to stop every hour or so and just walk around for a few minutes to keep the blood circulating.”

Echoing this sentiment, the current case study authors recommended that more research be directed at the health risks associated with intense gaming. “With the growing popularity of video games, the burden of this presentation of venous thrombosis is likely to increase,” they wrote in their conclusion. “Further studies are needed to estimate the degree of risk associated with prolonged periods of playing video games, and education for preventing venous thrombosis should be provided to gamers.”

Source: Hsien-Cheng Leon Chang, Hayley Burbridge and Conroy Wong. “Extensive deep vein thrombosis following prolonged gaming (‘gamer’s thrombosis’): a case report.” Journal of Medical Case Reports 2013, 7:235 doi:10.1186/1752-1947-7-235