I Had A Friend Who Died A Few Years Ago.

I had a friend who died a few years ago. I saw him a few days before he was found dead in his house and he looked terrible to me. I asked him if he had seen a doctor for the cold he had had for a few weeks and he said he was getting over the cold. He was very pale and looked sweaty, his cheeks however were very pink, flushed like and he seemed to be breathing badly and had a hard time carrying something from his vehicle. He said his heart doctor had given him a good report just recently, (he had bypass surgery a few years before) and his diabetes was under control with insulin. He was a bit overweight. He had always gotten around well, he had lost the lower part of one leg due to an infection and the diabetes, but used an artificial leg and you would never know he had it. No autopsy was performed. What did he die of?