For Apple fans, there's nothing scarier than the recurrent medical issues the company's CEO, Steve Jobs, has faced over the past several years. Jobs' increasingly frequent absenteeism from the company has been caused by a host of serious medical conditions that have always been purposefully hidden from the public, and—it should be noted—from shareholders.

It's happening again.

In a typically terse press advisory, Jobs wrote that he was taking another medical leave of absence to focus on his health, and as with previous similar situations, no details were provided about the problem or his condition.

"At my request, the \\[Apple\\] board of directors has granted me a medical leave of absence so I can focus on my health," Jobs wrote in a Monday advisory. "I will continue as CEO and be involved in major strategic decisions for the company. I have asked Tim Cook to be responsible for all of Apple’s day-to-day operations. I have great confidence that Tim and the rest of the executive management team will do a terrific job executing the exciting plans we have in place for 2011."

Jobs has a now-long history of health problems that provide a backdrop of mystery and intrigue to his company's ongoing hype cycle with the media. In 2003, Jobs was diagnosed with pancreatic cancer, and after an ill-advised attempt at alternative medicine, he underwent surgery that at the time was described as almost miraculously successful.

A few years after returning to work, onlookers began commenting on how thin and wane Jobs appeared at press conferences, and in early 2009 he announced that he had a "hormone imbalance," noting that press "curiosity" over his health was "a distraction." But then, just two weeks later, he announced a sudden leave of absence. It was pretty clear that Jobs was suffering from something more serious than what was previously stated.

Jobs then underwent a secret liver transplant in Tennessee amidst charges that he had used his celebrity status to jump to the top of waiting lists. But a spokesperson for the Methodist University Hospital Transplant Institute in Memphis, Tennessee, said at the time that Jobs was simply "the sickest patient on the waiting list at the time a donor organ became available."

Jobs returned to work in June 2009, but he never regained weight and has continued to look thin and frail at the company's continuous press conferences, which are treated by the media as religious revival events instead of the product announcements they are. A big part of the reason for the hype, of course, is Jobs—a master showman and product seller who clearly delights in his role in the spotlight.

Monday's press advisory reads almost exactly like the one Apple issued in January 2009, with the same stated optimism for the company's upcoming products, while noting that the capable Tim Cook will be responsible for Apple's day-to-day operations. And with Apple set to announce what are expected to be blockbuster financial results Tuesday, the company would normally be riding quite a high at this moment.

But now, as in the past, Jobs' health is overshadowing everything. The issue, as before, is one of succession: There simply isn't anyone, inside or outside of Apple, who can effectively follow in Jobs' footsteps. He is unique, an icon, and not just in the tech industry. He's a man who could sell snow to Eskimos, as the saying goes, but can also captivate a crowd like no other.

Best of luck, Mr. Jobs. At moments like this, the partisan technology bickering fades into the background. We are all rooting for you.