We often hear the phrase 'growing pains' used by the general public to describe muscle or joint pain in young people and the term is also used by health professionals. However researchers have found there is no consistent medical definition of the condition behind a diagnosis.
A broad review of medical literature by University of Sydney researchers found there is no agreement among researchers and clinicians on what growing pains really are, what they mean, how they are defined, and how they should be diagnosed.
The researchers say growing pains may be a medical misnomer. Surprisingly, more than 93 percent of studies did not refer to growth when defining the condition.
More than 80 percent of studies made no mention of age in their definition.
The findings have prompted the researchers to recommend the term growing pains not be used by clinicians and other researchers as a stand-alone diagnosis, until a clear definition backed by evidence has been established.
The study is published in Pediatrics.
Growing pains are considered to be one of the most common causes of recurring musculoskeletal pain in children and adolescents. Some studies suggest up to a third of children experience the condition at some point in their life.
The term first emerged in 1823 in a book called 'Maladies de la Croissance' ('diseases of growth').
"Thousands of kids are diagnosed with growing pains by their healthcare professional, but we were curious – what does that diagnosis really mean?" said lead author Dr Mary O'Keeffe from Institute for Musculoskeletal Health at the University of Sydney.
The researchers extracted information from 147 studies that mentioned growing pains.
The goal was to see how researchers defined the term, and if there were any detailed criteria that led to a diagnosis. The medical literature included research of many types including systematic reviews, editorials, observational studies, case-control studies, and theses.
"What we found was a little concerning: that there is no consistency in the literature on what 'growing pains' means," said Professor Steven Kamper, from the School of Health Sciences at the University of Sydney and Nepean Blue Mountains Local Health District.
"The definitions were really variable, vague and often contradictory. Some studies suggested growing pains happened in the arms, or in the lower body. Some said it was about muscles while other studies said joints."
Only seven studies, less than 10 percent of the studies examined, mentioned growth related to the pain. More than 80 percent of the studies did not mention a young person's age at the time 'growing pains' occurred.
There was also no widespread agreement or a lack of detail on where the pain was located or when the pain happened.
Fifty percent of studies referenced 'growing pains' as being located in the lower limb, while 28 percent reported specifically in the knees.
Forty-eight percent of studies reported the 'growing pains' happens during the evening or night and 42 percent reported it was recurring.
"What this study uncovered was while 'growing pains' is a very popular label used to diagnose musculoskeletal pain, it means very different things to different people," said senior author Professor Steve Kamper.
"This level of uncertainty means clinicians don't have a clear guide or criteria to know when the label 'growing pains might be appropriate for a patient'."
The study also raised new questions on whether growing pains have any connection to growth itself in bone or muscle.
"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," said Dr O'Keeffe.
"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."