If you get ill in the United States, you just might go bankrupt. A Harvard University study found that about half of all personal bankruptcies in America are caused by illness and medical bills.

Researchers from Harvard Medical School and Harvard Law School analyzed federal court records of 1,771 personal bankruptcy filers in five American states in 2001. The researchers interviewed 931 of them about their finances.

About half of the personal bankruptcy filers cited illness or injury as the reason for their debt.

"Unless you're Bill Gates you're just one serious illness away from bankruptcy," said lead researcher Dr. David Himmelstein.

More than 75 percent said they were insured at the start of their illness, but 38 percent had lost coverage, at least temporarily by the time they filed for bankruptcy.

The researchers said health insurance policies, with high deductibles, co-pays, and many exclusions, offer little protection.

Among those whose medical bills contributed to their bankruptcy, the study found out-of-pocket costs averaged $11,854. Those with cancer had average medical debts of $35,878.

The study's authors said between 1.9 million and 2.2 Americans experienced "medical bankruptcy" in 2001.

Writing in the journal Health Affairs, the researchers said, "The low rate of medical bankruptcy in Canada suggests that better medical and social insurance could greatly ameliorate this problem in the United States."