The term 'growing pains' has been used for hundreds of years to describe aching sensations many children experience in the course of their development. For such a widely accepted concept, however, there's surprisingly little to define the diagnosis.
Indeed, the term is so overly simplistic, some researchers say it's virtually meaningless.
A recent review of literature on growing pains found no scientific consensus on any aspect of the condition, including when the pain starts, where it occurs, how often it hurts, how much it hurts, or even why.
Among all 145 peer-reviewed studies included in the review, there was much disagreement.
Some studies pinned the location of growing pains to the legs. Others to the arms. Some research said the pain occurred on both sides of the body. Others said it was isolated to just one.
Nearly 40 percent of the research didn't even bother to mention where the pain was located at all.
What's more, 83 percent of the studies didn't reference the age of onset, making it difficult to determine what aspects of child development could possibly be triggering the pain. In fact, only 5 percent of the studies mentioned growth at all.
"This lack of clarity along with the generally accepted view that pathophysiology is unknown raises the possibility that 'growing pains' is a misnomer," the authors of the review write.
This probably hasn't done a whole lot of damage, given that growing pains appear to be benign and treatable, but it is surprising to note that such a commonly cited condition remains shrouded in so much mystery and myth.
Because scientists know so little about it, the authors of the review say doctors and researchers should be specific about their clinical criteria when diagnosing someone with growing pains.
The authors aren't the first to criticize the haziness of the condition, either. Other researchers in the past have wondered if growing pains are merely a diagnosis of exclusion, after all other types of known pain conditions have been accounted for.
A recent study that tried to use a clear and consistent definition of growing pains found that up to 37 percent of parents reported that their 4-, 5- and 6-year-old children experienced recurrent leg pain.
Subjective measures such as self-reporting can leave plenty of room for interpretation, but results like these suggest there are quite a number of young children suffering from some level of limb pain.
If the condition does, in fact, have a distinct physiological basis, then we know next to nothing about it. Over the years, researchers have put forward numerous explanations for growing pains, from stress to anatomy to nutrition, though none have been thoroughly tested.
"There is a lack of evidence or inconsistent information on growing pains as a condition – and how it is associated with growth, or even the cause of the pain," says physiotherapist Mary O'Keeffe from the University of Sydney.
"There is a real opportunity to understand this condition – given how widespread the use of the term is, or whether there is even a need to use this term."
We owe it to the kids to do some more research.
The study was published in Pediatrics.