Last reviewed October 23, 2012
By Robert H. Shmerling, M.D.
It seems to make sense: If a child or teenager who is going through a growth spurt complains of leg pain, it's probably just "growing pains," right? But what exactly are growing pains? And if they are truly related to growth, a number of questions arise:
Whatever they are, the description of growing pains goes back a long way. The typical case is a child between the ages of 12 and 17 who develops mild to moderate (and occasionally intense) pain in the calves, shins, knees or thighs. The pain is often not confined to one spot or one area; it tends to affect the entire leg. Pain may be most severe at night and may intensify then for 10 to 15 minutes, but it is rarely debilitating. It does not typically prevent walking, running or participation in sports. There is no fever, redness of the skin, or swelling in fact the legs and other areas of pain appear completely normal. These pains may last a few weeks or months but rarely become chronic. Then, as mysteriously as the pain appeared, it resolves.
There does seem to be something to the concept that during childhood, when growth is most rapid, pain in the most rapidly growing bones (the legs) is common. After puberty, at about the time that the most rapid growth is complete, the incidence of these pains is lower. The timing alone is proof enough for many that growing pains are related to growth, especially when no other cause of pain can be found. Pediatricians commonly use the term, though there is no clear consensus regarding its definition or cause.
On the other hand, all healthy kids grow and not all of them have growing pains, so there must be some other contributor or explanation. In addition, there is no evidence that rapid growth or tall children have more growing pains than their shorter classmates. In addition, the pain tends to involve areas of the body where growth is not actually occurring: Growth plates tend to be near joints, while growing pains tend to be all over or in the front of the shins between the knee and ankle joints.
A 1999 study reviewed the available research and concluded that "growing pains is an accepted medical term, though the pains are not due to growing" and a study in 2001 of children ages 12 to 18 found no correlation between pain and growth. Some experts believe "growing pains" are actually due to muscular injury, strain or even small tears that occur over the course of a child's activities. If this is the reason for growing pains, the actual injury is frequently not recalled. Recommended treatment is massage, ice or heat, and acetaminophen. Sometimes, ibuprofen, topical treatments (such as the IcyHot Medicated Sleeve or BenGay) are helpful.
Once serious conditions are ruled out (see below), reassurance is also important. Whatever "growing pains" are, they are not dangerous. Children (and their parents) may privately worry a great deal about them, so learning that these pains are common and ultimately harmless can do a world of good for peace of mind.
Bones grow during childhood by lengthening around the "growth plate," a special area near the ends of long bones that allows rapid addition of bone throughout childhood, with a rapid acceleration around puberty. Closure of growth plates in long bones that occurs toward the end of adolescence spells the end of bone lengthening. However, bones continue to thicken and remodel, especially when stress is applied, as, for example, during athletic activities.
Injuries to the growth plate may cause serious problems in bone development. For example, if a child fractures a bone through the growth plate, that bone may not grow evenly, or it may stop growing prematurely. This is one reason that overuse or traumatic injuries to children can cause significant problems later in life. Its also why increasing attention is now paid to stretching, strengthening and conditioning prior to and during competitive sports, well before varsity high school and college sports programs begin.
As far as we know, the growth plate is not a source of pain, even when it is at its most active. Unless there is an injury, normal lengthening of long bones is not a painful process.
A number of conditions may cause leg pains in kids. Some of the most common are minor strains, sprains or other injuries. Although rare, serious conditions may begin with pain in the joints or legs, including:
These are usually accompanied by other symptoms such as pain that persists throughout the day, limping, fever, swelling, loss of appetite, fatigue, rash, the need to move the legs to relieve symptoms or other unusual behavior. These symptoms would not be expected to accompany "growing pains" and should prompt medical evaluation. For the vast majority of children, a review of symptoms and past medical problems, a thorough examination, and simple testing can identify these other causes.
"Growing pains" occur in young people who are growing, but the pain is not clearly related to growth, and there is no clear disease present to account for pain. The notion of growing pains as a medical disorder directly related to bone growth is probably a myth, although these pains are common and their cause is uncertain. On the other hand, whether we call it "growing pains" or some other name is not the most important issue. The most important consideration is that a serious or even dangerous medical condition is not overlooked and that the pain is treated effectively. Remarkably, very little has been published in the medical literature on this common malady. Perhaps some day, additional studies will clarify the cause, but until then, "growing pains" may still be a useful name for pain occurring in growing kids, even if not truly related to their growth.
Robert H. Shmerling, M.D. is associate physician at Beth Israel Deaconess Medical Center and associate professor at Harvard Medical School. He has been a practicing rheumatologist for over 20 years at Beth Israel Deaconess Medical Center. He is an active teacher in the Internal Medicine Residency Program, serving as the Robinson Firm Chief. He is also a teacher in the Rheumatology Fellowship Program.