
There are three major components: Price, Population, and Usage.
Price
Medical services prices increased, room rates increased and physician rates increased. These costs have outpaced the growth of general consumer prices.
Population
Population growth during post WWII and recent increase in large population over 65. This population requires more doctor visits, have a higher rate of hospitalization that result in longer days stayed.
Usage
Government and health insurance programs allowed the poor and elderly enhanced usage. The increased elderly population results in higher usage volume and new technologies require hospital visits.