The head of the major health insurer that wants to boost rates in California by up to 39 percent defended her company for some individuals before Congress on Wednesday, revealing that the increases would be difficult for many customers but were necessitated by surging medical costs.

In testimony developed for a U. S. congressional hearing on Wednesday, Chief Executive Officer Angela Braly posted that the 25 percent average increase for certain Anthem Blue Cross customers in California was "unfortunate" though "necessary." She called on lawmakers to target other industries' costs as they work to revamp the nation's healthcare system.

"Raising our premiums was not something we wanted to do -- but we believe this was the most prudent choice", Braly cited. "All health insurers are in the same position, and even with this increase, our company's premiums remain quite competitive", she added.

Anthem involves more than 8 million Californians, including about 800,000 who buy their policies directly. It is on those individually covered people that Anthem has proposed rate increases of up to 39 percent. However, the company posts the average increase is 25 percent -- which the company says is in line with competitors.

Braly claimed the rate hikes and surging costs signify the reason why a health overhaul is required. She said the Democratic bills debated so far have been inadequate because they don't control the growth of medical costs.