By Rennie Dyball Karen S. Schneider
October 22, 2007 12:00 PM

At first, Isaac Hanson didn’t think it was serious. On Oct. 2 the 26-year-old guitarist was about to take the stage at the House of Blues in Dallas with the other two-thirds of the band Hanson—brothers Zac, 22, and Taylor, 24—when “my shoulder started to irritate me,” he says. Chalking up his discomfort to a grueling 35-city tour and years strumming the guitar as part of a family act that became a ’90s teen pop legend with hits like “MMMBop,” he popped an aspirin and went on. But as he began to play, his right arm felt so sluggish that he alerted his wife, Nikki, with whom he’d just celebrated his first wedding anniversary. Watching from offstage, she became alarmed. By the end of the concert, “his arm was purple and swollen,” she recalls. “That’s when my heart dropped.” Her husband was also scared. “I felt panic—without screaming,” he says. “I said, ‘We’ve got to find a hospital. Immediately.'”

A day later Hanson was on an operating table at Baylor University Medical Center at Dallas, undergoing surgery for a condition that “was life threatening,” says his surgeon Dr. Brad Grimsley. In 2003 Hanson had been hospitalized for thoracic outlet syndrome, a sometimes painful compression of the blood vessels that can be caused by repetitive action like guitar playing. In most cases, the condition is easily treated—and since he’d long had shoulder troubles, Hanson wasn’t worried when he first felt the pain onstage. But in a small number of cases, sufferers develop potentially lethal pulmonary embolisms (see box). In Hanson’s case, a blood clot in his arm had traveled to both his lungs, where it could have triggered heart failure. “The scary part is you’re not necessarily in pain,” says Hanson. “I could have silently died.”

As he prepared for surgery, Hanson (known as Ike to his family) tried to focus on being “the best patient I could be.” He also focused on his son Everett, who celebrated his 6-month birthday on Oct. 3. “I told my wife, ‘If only Everett was here. I bet he could fix my troubles,'” he recalls. Adds Nikki: “We were joking around that ‘I was in your position six months ago, laying in a hospital bed.’ But when we talked about Everett, we both started crying. Because what if something happened? He would not have a father…. I was freaking out on the inside.”

So were Zac and Taylor, unsure whether to return to their hometown of Tulsa, where they were scheduled to play on Oct. 3. “Ike said, ‘You guys need to go,'” says Taylor. The brothers agreed in part; they canceled the show but did a preconcert charity walk for TOMS Shoes, which donates footwear to children in Africa. Says Zac: “We’re like, ‘We’re gonna continue working, and Ike’s gonna die?'”

Those fears were allayed after surgeons removed the clot on Oct. 4. Hanson is now embolism free and on a course of three blood thinners that should prevent future clots—but he’s not entirely out of the woods. In December he will have an operation to remove a rib that is pressing against a vein. “If I had my druthers, I would have kept him in the hospital for the rib resection,” says Grimsley. But Hanson was concerned about the six-week recovery period—and eager to finish touring through Nov. 13. So, with Dr. Grimsley’s okay, all three Hansons once again hit the stage on Oct. 8 in Knoxville, and Isaac was once again strumming his guitar—and counting his blessings.

“I’ve got angels watching out for me,” he says of support from friends and fans. “Flowers, e-mails—I got messages from people saying they were praying for me who I didn’t even know prayed!”

He’ll take all the help he can get. Until he has surgery, “I need to be really careful,” says Hanson of monitoring his health. And if he forgets, his family won’t. In a dressing room after the Knoxville concert, Taylor puts a hand on his brother’s shoulder and instructs, “Ice your arm.” Then Nikki insists he lift a bag with only his left hand. It’s all worth it, he says, for moments like, oh, being awakened in the middle of the night by Everett: “Even when he’s screaming at the top of his lungs, I’m thinking, ‘You’re just so cute,'” says Hanson. “Death is always a reality, and life is incredibly short. I’m a really, really lucky guy.”