Miscreant Michael Lohan's substance abuse issues have once again taken a back burner to his chronic health problems. According to Radaronline.com, the 51-year-old hothead was attending a mandatory AA meeting when he hit the floor... and not in a fun way. Although he has a history of crying wolf and feigning illness to escape his legal woes, this time it was legitimate. The Celebrity Rehab reality star collapsed after feeling lightheaded during the group session. A source says that Lohan was immediately rushed to the hospital, "He was taken in an ambulance to Palm Beach Gardens Hospital where doctors found another blood clot in his lung." At the hospital, Lohan was medicated in an attempt to break down the clots. Doctors also did an MRI to ensure that the clot hadn't spread to his peabrain. Lohan's stint in a court-appointed rehab for 120 days has been marred by ongoing health problems. Earlier this month, he had surgery on a clogged artery and was re-admitted to the hospital after getting a staph infection. So far there's no word on when Lohan will be "free" to leave the hospital, but one thing is for sure -- he's headed right back to rehab.