China's economy is on steroids, and things could get messy when they run out

China's economy has been given a dose of steroids. 
Lending in the country has exploded: Chinese banks have extended more loans in the last three months than the entire US corporate-financing market ever has, according to Deutsche Bank.
There have also been several rounds of relaxation in property-purchase regulations, according to Morgan Stanley.
The government has stepped up spending too, with the fiscal spending-to-GDP ratio increasing 2 percentage points&nb