Rumors around Steve Jobs' health have been circulating for months now. Each time a new one pops up Apple stock takes a hit. Some of those rumors have, of course, proved totally unfounded. The concern gained ground recently when Jobs decided not to give the keynote address at Macworld. Today, Jobs put investors' fears at ease by saying that doctors have finally determined the cause of his recent weight loss. The problem stems from a hormone imbalance, the remedy for which is simple, but will take some time to control. Jobs assured investors he will continue on as Apple's CEO and the board of directors voiced their full support of Jobs. Apple's stock rose more than 3 percent in early trading today.