"If the doctors had an electrical engineer take a look, he would find what the problem is that is causing the pain," explained Lonnie Zeltzer, director of the Pediatric Pain Program at Mattel Children's Hospital at UCLA. "It is a nerve signaling problem. There are pain signals getting to the brain so the child really feels pain, but the body's control system is not working well."
Zeltzer gives a hypothetical example of a family coming down with the stomach flu. Everyone in the family has the belly pain, diarrhea, nausea, etc. While everyone else gets better, the child -- who has not necessarily had pain before -- may continue suffering the stomach pain without the other symptoms.
"This is because … the brain-gut nervous system has become [un]regulated, causing increased sensitivity of the intestinal tract," she said.
Goldschneider agreed. "Just because we can't measure, X-ray or test to find the pain, doesn't mean it's not real. It means that in 2005, we don't yet have a way to measure it."
"Pain is a signal that something is wrong, the body is being harmed, so do something," he said.
Parents are key to their child's diagnosis, according to experts. They are the ones who spend the most time with them and know their reactions and facial expressions.
"Most parents know," Goldschneider said succinctly.
Zeltzer has written a book called "Conquering Your Child's Chronic Pain: A Pediatrician's Guide for Reclaiming a Normal Childhood." She said parents' contributions are important.
"... Parents play a significant role in helping their child to climb out of chronic pain or even help buffer their child from developing pain," Zeltzer said.
Parents and family also contribute to coping skills, Zeltzer said. An anxious mother who becomes alarmed whenever her child complains about pain could teach her child how to pay attention to physical body systems differently than a mother who tells her child that it's just a normal ache and it will go away.
A parent will know if there is sibling rivalry, if there are problems at home, a bully at school or an injury that happened years ago that could have started the process.
If a child keeps complaining of pain, even after test after test after test, a parent should know not to give up.
So how does one treat pain in a child when they cannot pinpoint exactly what's causing it?
All three experts agreed that the key to treating chronic pain in children is taking a multidisciplinary approach -- physical and psychological -- to help the child function with the pain they are feeling.
"Most physicians approach kids differently," Joseph said. Children get the appropriate pain medication at a rate of 20 percent to 30 percent less than adults do, he said.
Doctors fear two things when treating a child with pain medication: overdose and addiction. A number of physicians fear giving a child too much pain medication, so they give them too little, Joseph explained.
In addition, medications most often used to treat pain in adults have not been studied in children. "So those of us treating pain in children often have to rely on the adult studies for drugs in which there are no FDA [Food and Drug Administration]-approved indications in children," Zeltzer said.
But treatment should not be limited to medication.
"Our goal is not always to treat the pain, but to facilitate function," Joseph said. "To help the child become happy, healthy people, we treat the pain to help them get to that point."
Zeltzer noted non-drug strategies such as hypnotherapy, biofeedback, massage, yoga and acupuncture.
Goldschneider said it's important to look at the whole picture to treat pain effectively. His clinic gives children a functional assessment, a physical assessment, a psychological assessment, looks at how they are able to cope with the pain and more.
"When you have a complete picture," he says, "deciding how to treat it becomes easier."