They're creepy, crawly, and blood thirsty, but it turns out leeches are also life savers.
"Leech therapy is most successful when you have a veinous injury in which your veins are no longer draining appropriately," said Dr. Pedro Rodriguez, OSF Medical Group.
And that's the case of DeKalb resident Sam Leon. His hand was ripped to shreds in a rollar type press machine.
"The pain wasn't bad, I really think it happened so fast that it ripped my nerves off and i didn't even feel it," said Leon.
"The skin of his hand including all the fingers had been ripped off from this press injury that occured at work," said Dr. Brian Bear, Rockford Orthopedic. "When that happens, it tore all the veins, many of the nerves some of the arteries to his hand."
Dr. Bear says Leon should've lost his hand, but thanks to more than 1,400 leeches, the result was different.
Doctors say leeches do two things critical to injuries involving veins: they reduce pressure, and keep blood from coagulating, allowing it to drain. The leeches have proved successful, but they certainly aren't comfortable.
"Those leeches biting on that nail bed is the worst pain I have ever felt," said Leon.
Doctors admit, they had their doubts over whether it would actually work.
"The hardest thing was if this doesn't work, and we have to go back and do other types of flap coverage that will take months to get him something that is one-eighth as good as he has now," said Dr. Bear.
Looking at his hand now, Leon says the ancient treatment was well worth it.
"I'm glad I have my hand, and to this day it's still improving."
Doctors say Leon's hand will never be 100 percent healed, but Leon feels good about all the progress he's made.