Bernie Mac had a little known disease called sarcoidosis, the same disease that Reggie White had. The disease itself can't kill you but it inevitably causes other complications that do kill you. Pneumonia being one, as well as asthma, emphysema and other lung diseases.
Very little is known about the disease. Doctors don't know what causes it and there is no cure. Steroids can help but at the levels you need to take them sometimes the side effects are worse than the disease.
I'll tell you what, this news scares the hell out of me because both Reggie White and Bernie Mac died young due to lung complications created by sarcoidosis and because I also have the disease.
Rest in peace, Bernie Mac. You always put a smaile on my face.