"The tissue and mucus membrane in the nose and throat of younger teens are very sensitive because they're growing," so when they inhale the substances not only are they more subject to the effects, but they may be more susceptible to long-term problems such as brain and organ damage, and possibly cancer, she said.
Other long-term effects of huffing include damage to the heart, kidney, brain, liver and other organs.
"Brain and memory are the most affected," Caudle said. "You have young people developing dementia, having hallucinations, walking into things -- not to mention feelings of agitation and anxiety and poor judgment."
Inhalants also produce withdrawal symptoms for users who try to quit, because the chemical high produced by sniffing is both physically and psychologically addictive.
What's more, sniffing can be a "gateway drug" for teens. In a 2007 study by SAMHSA, researchers found that 17 percent of teens who started using drugs in the last year reported that inhalants were the first drug they started using.
In 2007, nearly 1 million teens admitted to using inhalants in the last year and 100,000 of these would qualify as addicted to or abusing inhalants, according to SAMHSA's data.
Kevin Talley and his wife, Deborah, knew something was up with their daughter but never suspected she was using inhalants, he said. Even an ear, nose and throat doctor they took her to two weeks before her death couldn't pinpoint why Amber's throat was so inflamed and why she was acting so strange.
"I'm not sure many parents actually know about sniffing," Caudle said. "It's been around for years, but there's not been enough awareness. People don't get how big of an issue this is."
So what are the signs that a teen is using inhalants?
According to Bergen-Cico, the two key markers are physical evidence of use and behavioral changes.
Physical evidence would include finding empty aerosol containers, items containing noxious fumes missing from the household, rags, plastic bags, or strange stains or odors on teen's clothing.
Behavioral signs of use, she said, often mimic alcohol intoxication with slurred speech, glassy eyes, poor muscle coordination, nausea, stumbling and/or dizziness. Mood changes are also common, and parents may notice that their children "aren't themselves," Caudle said.
In Amber's case, Talley said she would lose her temper at the drop of a hat, had glassy eyes and her clothing had a strange, pungent smell -- all signs that would have pointed to sniffing had the Talleys known to look for them.
Beyond awareness, it's important to address the root of these problems as well, Bergen-Cico said.
"When we see people younger and younger using things to get high on, the key issue is not just how to stop them but why are they looking to get high?" she said. "What are they trying to escape?"