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What Is Pain
Pain is normal. About 75 million U.S. residents endure chronic or recurrent pain. Migraines plague 25 million of us. And one in six suffer arthritis.
The global pain industry pulls in more than $50 billion in drugs a year. Yet for chronic pain sufferers, over-the-counter pills are typically little help, whereas morphine and other narcotics can be addictive sedatives.
An overview study published in 2008 in the Journal of General Internal Medicine looked at multiple studies of pain and found "researchers don't yet know how to determine which [treatment] is best for individual patients." From studies of drugs to surgeries and alternative medicines, "We have found that there are huge gaps in our knowledge base," said Dr. Matthew J. Bair, assistant professor of medicine at the Indiana University School of Medicine.
Here's a look at six surprising facts about that achy sensation whose scientific understanding is painfully fuzzy.
Scientists don't understand painSlide 2 of 11
Scientists don't understand pain
When you're in pain, you know it. But if scientists could fully grasp how pain works and why, they might be able to help you more. The American Academy of Pain Medicine defines pain as "an unpleasant sensation and emotional response to that sensation." More scientifically, pain is felt when electrical signals are sent from nerve endings to your brain, which in turn can release painkillers called endorphins and generate reactions that range from instant and physical to long-term and emotional.
Some pain is the result of an obvious injury. Other times, pain results from damaged nerves that are not so easy to pinpoint. "Pain is complex and defies our ability to establish a clear definition," said Kathryn Weiner, director of the American Academy of Pain Management. "Pain is far more than neural transmission and sensory transduction. Pain is a complex mixture of emotions, culture, experience, spirit and sensation."Slide 3 of 11
Pain may shrink the brainSlide 4 of 11
Pain may shrink the brain
If you have chronic pain, you know how demoralizing and debilitating it can be, physically and mentally. It can prevent a person from completing routine activities and skyrockets one's irritability for reasons "others" don't quite understand.
But that's only half of the story. The brains of people with chronic backaches are as much as 11 percent smaller than those of non-sufferers, scientists reported in 2004. Scientists aren't sure why. "It is possible it's just the stress of having to live with the condition," said study leader A. Vania Apkarian of Northwestern University. "The neurons become overactive or tired of the activity."Slide 5 of 11
Painful migraines and sex go hand-in-handSlide 6 of 11
Painful migraines and sex go hand-in-hand
It may not eliminate the phrase "Not tonight, honey ..." but a 2006 study found that migraine sufferers had levels of sexual desire 20 percent higher than those suffering from tension headaches. The finding suggests sexual desire and migraines might be influenced by the same brain chemical, and getting a better handle on the link could lead to better treatments, at least for the pain portion of the equation.Slide 7 of 11
Women feel more painSlide 8 of 11