In search of euphoria, heroin users devastate their bodies and minds. Twenty-three percent of people who try it at least once become addicted, according to Dr. Charles O'Brien of the University of Pennsylvania.
"For most, addiction is a lifelong disease," said O'Brien, a professor of psychiatry at the Penn Medicine Neuroscience Center.
Heroin's most vicious attack is on the brain. The powerful narcotic activates the brain's natural opioid receptors that regulate pain, reward and pleasure and highjacks their pathways. That euphoric high leads to physical changes in brain molecules, Dr. Joshua Lee of the NYU Langone Medical Center said.
O'Brien says heroin also "creates memories." For recovering addicts, just smelling or seeing heroin can trigger intense memories with uncontrollable cravings.
And there is always the chance of a deadly overdose. "On too much heroin, breathing slows down or stops completely," said Lee.
During heroin withdrawal, the "brain typically registers high stress, anxiety and sleeplessness," said Lee. On heroin, blood pressure and heart rate slow down, but they race up during withdrawal, O'Brien said.
Users also report feeling intense aches, muscle pain, restless leg, bone pain and skin crawling sensations during withdrawal. On heroin, pain is suppressed, but afterward the pain control system becomes hyper-sensitive, amplifying every discomfort, O'Brien added.
Finally, heroin activates millions of natural opiate receptors throughout the body. For example, heroin paralyzes the gut, which then becomes hyperactive during withdrawal causing nausea, vomiting and diarrhea, O'Brien said.
Lee said heroin also triggers a histamine release that leads to tears, runny nose, sweating and itchiness.
Probably the greatest danger of heroin, say experts, is physical dependence. "While a typical dose doesn’t directly destroy your brain, overall the addiction can destroy your life," said Lee.