Diseases..! Are They?

Take sometime and ponder yourself on those good olden days where our great grand parents led a peaceful, healthy life, hospitalised very rarely if not never at all. Say you transported (in thoughts) to those days and be there. Just look around and see what people are suffering from Malaria, Plague, Tuberculosis... Have you heard of more people dying due to heart attacks, kidney problems, Alzheimer's ... Now come back to the present days, do you still find those old diseases Malaria, Plague, Tuberculosis as prevailing diseases. No, Thanks to advanced Medical Research. We got rid of them long back. Are we free from diseases? Are we leading a Healthy life?
What are the present haunting and lifethreatening diseases?
Alzheimer's, Parkinson's,Heart Attack, Obesity...

Let me sow some seeds in your head to keep your mind ticking/thinking.
Are we treating diseases?
Is our approach (Medically) apt?
Is there any alternative?
First of all are they diseases?
If these are not diseases then What are they?