Synthetic drugs—substances that mimic the effects of marijuana, cocaine and other illegal drugs—are causing a sharp rise in serious health problems ranging from seizures and hallucinations to death. The Associated Press (AP) reports that synthetic drugs, often sold as incense or bath salts, can be bought for as little as $10 in head shops. Hospitals are seeing a rapid increase in synthetic drug users with problems including breathing problems, rapid heartbeats, delusions and extreme paranoia.

Figures from the American Association of Poison Control Centers show at least 2,700 people have gotten sick from synthetic drugs since January, compared with fewer than 3,200 in all of 2010. At that rate, medical emergencies stemming from synthetic drugs could rise nearly fivefold by the end of 2011, according to the AP. The drugs are suspected in at least nine deaths in the U.S. since last year.

One of the most popular synthetic drugs, bath salts, are crystallized chemicals that users snort, swallow or smoke. The two powerful stimulants in the salts mimic cocaine, LSD and methamphetamine. In the first three months of 2011, poison control centers received more than 1,400 calls for bath salts, compared with 301 in all of 2010.