Zhang Xiaogang, age 54, a Beijing-based painter whose hypnotic portraits have topped $10 million at auction, recently suffered a pair of heart attacks, and his doctors told him - for the first time in his three-decade career - to rest.

Few artists embody China's art boom better than Mr. Zhang, who grew up amid the Cultural Revolution and gained fame for his large, haunting depictions of families dressed in Mao jackets and comrade's caps. Yet his desire to keep breakneck pace with China's developing art scene has taken a toll.

Mr. Zhang still spends his days at his soaring studio in a traditional village on the city's outskirts. His major collectors include former Swiss ambassador Uli Sigg, Beijing entrepreneur Liu Lan and Chinese-Indonesian farming tycoon Budi Tek. His earliest works fetch higher sums than ever at auction: In April 2011, 'Eternal Love,' a 1988 painting that he originally sold for $2,000, resold at Sotheby's Hong Kong for $10.2 million, an auction record for Chinese contemporary art.

But he said he's still learning how to navigate the pressures and expectations of the job. Six weeks after that record sale, Mr. Zhang was sitting in his studio with his 18-year-old daughter when he clutched his chest, struggling to breathe. Soon after, he underwent emergency bypass surgery to repair a blocked artery in his heart, his second heart surgery in 10 months. Afterward, his doctor told the artist he had to dramatically alter his lifestyle: No more whiskey or cigarettes (he was smoking two packs of Zhongnanhai a day) and no work-related stress for a year.

When artists break out in art hubs like New York or London, they can usually look to experienced galleries to broker their sales and help manage their careers. China didn't have a single privately run art gallery when Mr. Zhang got his start in the early 1980s. For a long stretch, he single-handedly managed his own career, juggling demands from dealers and collectors and occasionally making artworks on commission. (Mr. Zhang is now represented by Pace Gallery.)

Now, his health scare has given him an excuse to slow down and reassess his art. Of his roughly 600 oil paintings, a third are part of 'Bloodlines,' a series he began in the early 1990s inspired by the kind of quasi-patriotic family portraits that were popular throughout China during the Cultural Revolution. In Mr. Zhang's versions, these clusters of men, women and children appear glassy-eyed and unsmiling - bound by blood but possibly little else. Mr. Zhang has become indelibly linked to this series, and he continues to paint these works on occasion, even though they serve to criticize China's Mao era more than its current political situation. But there are signs that demand could be tapering off: Dealers say an early 'Bloodline' from 1994 can sell for as much as $8 million, but his recent versions of couples have sold for around $1.5 million. Mr. Zhang said some of his stress has come from his attempts to find his next big idea.

Mr. Tek, a collector who has paid as much as $6.7 million for Mr. Zhang's work, said, 'Getting a Zhang Xiaogang is like buying a historic movement frozen in art - he's classic. But he should slow down on the 'Bloodlines' because they're not as relevant anymore.'

During his hiatus from painting, Mr. Zhang is turning to a different medium: bronze. He is casting groups of large figures in bronze and will paint them by hand - a nod to the colorful polychrome statues that popped up throughout ancient Egypt and Ming-era China. Though he has dabbled in bronze occasionally, he has never tried this technique before. The figures themselves comprise his usual cast of 'Bloodlines' characters - a boy in glasses, a girl with pigtails. Gary Xu, a cultural historian at the University of Illinois at Urbana-Champaign, has seen the clay models and calls them 'fantastic.'

Mr. Zhang is part of an elite group of painters - including Fang Lijun, Zeng Fanzhi, Yang Shaobin, and Yue Minjun - who were once ignored by China's political leaders but are now hailed as cultural success stories. Beginning in the late 1980s, they experimented with modernism, expressionism and Pop at a time when Soviet Realism still held sway. Eventually, they helped kick-start a lasting conversation about what China's new art could look like. And as China's economy skyrocketed, so have their asking prices and reputations. Now, film director Zhang Yang said, these artists are 'better known in China than most movie stars.'

Mr. Zhang's friends say he has never felt entirely comfortable in the role of celebrity. He doesn't wear designer clothing, preferring jeans and Converse sneakers. For his part, he said one reason he started drinking heavily years ago was so he could shake off his natural shyness.

In May, Mr. Zhang sat in a hotel overlooking the vast Hong Kong Convention and Exhibition Centre, which had become a warren of art-filled booths for the region's major contemporary-art fair, Art HK. Glancing at the crowds, he said, 'You have to use your imagination to conjure how it was before all this.'

Anyone who visits Mr. Zhang's Beijing studio will likely notice his 'idea board.' This wall-size panel is covered with items he has pinned up for inspiration - from photos of artists he admires, like Franz Kafka and singer Sinead O'Connor, to movie-ticket stubs and photos of his first studio apartment in Kunming, the city in southwestern Yunnan province where he was born in 1958.

Memory is the central theme of Mr. Zhang's art - what we choose to remember, forget or distort. In 1966, Mr. Zhang was 8 years old and living with his family in Chengdu in southwestern China when Mao Zedong ushered in the Cultural Revolution, a decadelong attempt to rid China of anything antique or foreign. Schools were shut down and his parents were sent away to separate work camps to be 're-educated,' leaving him and his three young brothers to fend largely for themselves. Their mother, who was later diagnosed as schizophrenic, left them pencils and a sheaf of paper with instructions to doodle whenever they felt bored or tempted to roam outside.

Eventually, Mr. Zhang befriended a former art teacher who taught him the basics of watercolors. At 17, he took his pens and paper with him when he was assigned by the government to plant potatoes and wheat at a mountainside re-education farm. By the end of his two-year stint, a local party official had pulled him from the fields to paint revolutionary slogans. 'Art helped me transcend the miserable situation,' he said.

When China reopened its colleges in 1977, Mr. Zhang was one of only two students in his province admitted to the Sichuan Fine Arts Institute in Chongqing. He was a decade younger than his 20 classmates. There, he first encountered images of Western art - Vincent van Gogh, Paul Gauguin, modern abstract painters - along with Soviet Realists. 'It was like going from hell to heaven,' he said.

After graduation, though, he spent a decade in an existential, creative funk. He married an outgoing woman in Chengdu who loved rock music and later owned a bar. He spent his days teaching art at his alma mater and his nights drinking. His mother's schizophrenia worsened. At age 26, he suffered a gastric hemorrhage and he was hospitalized for two months.

Weng Ling, artistic director of New York's China Center, met him in Chongqing in 1986. He was an 'angry artist, writing poems and painting pieces that looked like sad songs,' she said. Leng Lin, an art-history student at the time who has since become his dealer at Pace, also saw a show of Mr. Zhang's art around that time and said the artist was primarily painting figures in toga-like robes surrounded by symbols culled from pagan, Christian and Buddhist faiths. 'He was wrestling with Europe,' Mr. Leng said.