Last one that I recall hearing about had the doctor telling him to tone down the drinking.
But I did find this as well:
Dr. Kuhlman also reported that Mr. Obama has been having periodic physical therapy to help him deal with recurrent back problems http://www.nytimes.com/2011/11/01/us/politics/obama-tobacco-free-and-fit-doctor-finds.html?_r=0
Could be he is on pain killers prescribed by the Dr.
Back problems due to either bending over to our enemies, or for Reggie Love, or both.