As technological advances allow a broader palette of life-saving surgeries, the organ and blood reserves that make these operations possible will continue to be in demand.

Blood and organ banks make up 55 percent of the $23.8 billion ambulatory health services industry, and the financial barriers to entering this field are relatively low, despite some regulatory hurdles. Perhaps a more surprising growth category in this industry is the increased demand for sperm donation. This is largely because a number of European countries have passed legislation that prevents sperm donors from remaining anonymous or receiving compensation.

This leads to a severe drop in supply, and now "you have all of those infertile people buying sperm from U.S. cryobanks," says Corey Whelan, the program director for the American Fertility Association.

By the numbers:

Percentage of total U.S. health industries' revenues represented by blood, organ, and ambulatory health services in 2009, according to IBISWorld: 1.2

Expected annual "blood, organ, and ambulatory health services" industry revenue growth through 2014, according to IBISWorld: 5 percent