More than 8,200 Americans—an average of 23 people each day—died of heroin overdoses in 2013. That's according to a new report from the Centers for Disease Control (CDC), and it's the latest evidence that the nation's heroin problem is becoming more severe. The rate of overdose deaths in 2013, the CDC report states, is almost triple what it was in 2010.

The growing heroin problem follows a decade-long increase in the abuse of prescription opioids such as oxycodone and fentanyl, which are chemically similar to heroin. Many more Americans continue to die from overdoses involving these kinds of prescription pills than heroin. But opioid-related deaths have declined slightly, while the rate of heroin deaths has increased since 2010. That was the year the OxyContin, a widely prescribed painkiller, was reformulated to make it harder to abuse.

Most people who abuse prescription painkillers don’t move on to heroin. But four out of five new heroin users have popped pills before, according to a 2013 government survey.

While the rate of overdoses climbed from 2010 to 2013, the number of heroin users increased by 68 percent from 2002 to 2013, far faster than the rate of U.S. population growth. Only 10 percent of that increase happened since 2010, when the CDC began to record a spike in heroin deaths.

The biggest spikes in heroin deaths have taken place in the Northeast and Midwest, the CDC reports. The demographics of heroin abuse and overdose are shifting. While heroin deaths are increasing among all races, the highest overdose rate in 2000 was among middle-aged blacks. By 2013, whites aged 18 to 44 had the greatest rate of overdoses. Men are nearly four times as likely to die from heroin overdoses than women are.

Heroin is also a big business: The RAND Corp. in 2010 estimated that America’s heroin market was worth $27 billion. That's more than what is spent in the U.S. at hardware stores ($22 billion) or specialty food retailers ($21 billion), according to Census Bureau data.

Sizing up black markets carries a big dose of uncertainty, though. RAND says the actual size of the U.S. heroin trade could be anywhere from $15 billion to $45 billion. Based on the latest data from the CDC, the drug's toll on Americans shows no sign of slowing.