INTRODUCTION — Recurrent, self-limited extremity pains for which the parents/caregivers, child, and health care provider have no explanation are often called "growing pains." These pains, also termed "idiopathic nocturnal pains of childhood" or "recurrent limb pains of childhood," are benign and usually resolve within a year or two of onset. However, growing pains may be distressing to patients and caregivers, and it is important to distinguish these benign symptoms from pathologic causes of pain that require additional investigation and therapy (table 1).
The epidemiology, etiology, clinical features, evaluation, and management of growing pains in children are reviewed here. The evaluation of children with joint pain and limp is discussed separately. (See "Evaluation of the child with a limp" and "Evaluation of the child with joint pain and/or swelling".)
DEFINITION — There is no consensus definition of growing pains. In general, the term "growing pains" is used to describe children with limb pain (most commonly lower extremity and bilateral) that occurs primarily late in the day or at night who are otherwise without any manifestation of musculoskeletal problems. This type of pain typically does not require evaluation beyond a complete history and physical examination. Children with unexplained joint pains that occur in association with activity or that are associated other systemic symptoms deserve further investigation. (See 'Diagnosis' below and 'Differential diagnosis' below and 'Evaluation' below.)
EPIDEMIOLOGY — Growing pains are the most common cause of episodic musculoskeletal pain in children. The prevalence varies from 3 to 37 percent depending upon the population studied, the age of the children, and the clinical definition used [1-5]. Surveys of schoolchildren indicate that as many as 10 to 20 percent have had growing pains [5-8]. Growing pains are slightly more common among girls than boys [2-4,9].
ETIOLOGY — The etiology of growing pains is not known. Although they occur in growing children, growing pains do not coincide with periods of rapid growth, do not occur at the sites of growth, and do not affect the growth of children who have them [10,11]. A systematic review on the etiology of growing pains found significant heterogeneity in the available studies, limiting the ability to make conclusions about probable etiologies [12]. The studies identified in their review covered a range of potential etiologies, but the most frequently studied categories were family history, lower pain threshold, foot posture, reduced bone strength, hypovitaminosis D, psychological disturbances, and overlap with restless legs syndrome.
Other proposed etiologies include fatigue, mild orthopedic and postural abnormalities, hypermobility, and local overuse [13-16]. Parents/caregivers of children with growing pains often reveal a pattern of increased complaints following an increased level of physical activity [17]. A study of bone speed of sound (SOS), a form of quantitative ultrasonography that is used as an alternative measure of bone density, provides support for local overuse as a contributing factor [15]. In this study, children with growing pains had decreased SOS compared with control children. Decreased SOS is also seen in patients with local overuse.
Several studies suggest that lower bone density and mechanical factors may also contribute to the development of growing pains. Supplementation with vitamin D in children with low levels was found to significantly reduce pain in two studies, and one of these studies also found improvements in the ultrasound bone assessments including SOS [18,19]. More specifically, two studies have looked at the occurrence of low vitamin D levels in children with growing pains [20,21]. One of the cohorts reported that 57 percent of children with growing pains had low vitamin D levels, while another found that 94 percent were deficient. However, neither of these studies included control groups for comparison with the general populations. Two additional studies tested the effect of vitamin D supplementation on growing pains [18,19]. While both reported improved serum vitamin D levels and decreased pain scores, neither included control nor placebo groups for comparison.
Another study found that shorter gestational age, low birth weight (<3000 g), smaller head circumference, and shorter birth length were associated with growing pains, factors that are also associated with lower bone content and density in childhood [22]. This study also found an association between genu valgum and growing pains, including in dizygotic twins, suggesting that this mechanical factor contributes to development of growing pains. A small study found that the use of foot orthoses to correct foot malalignment (commonly overpronation) and secondary genu valgum in children with growing pains decreased the frequency and level of pain and improved their balance ability within one to three months [23].
Another proposed etiology is lower pain threshold. In population-based studies, growing pains are consistently associated with other recurrent pains such as migraine headache and abdominal pain [4,9,24-26]. In one study, children with recurrent headache (45 percent of whom also had growing pains) were more often described by their parents as having greater sensitivity to pain, greater reaction to stressful situations, and more depressive symptoms compared with matched controls [24]. In another study, children with growing pains were found to have a decreased pain threshold compared with control children [27]. (See "Tension-type headache in children" and "Chronic abdominal pain in children and adolescents: Approach to the evaluation".)
Results from one study suggest that there is a hereditary component to growing pains; 70 percent of children with growing pains had a family member with growing pains [5]. A study of monozygotic and dizygotic twins also supported familial occurrence of growing pains and possible share genetic determinants with restless leg syndrome but was limited by the use of surveys and parental recall [28].
CLINICAL FEATURES — Despite the varying case definitions for growing pains, certain common clinical features emerge, including the following [2-4,6,7,9,27,29-31]:
●Growing pains usually begin between ages 3 to 12 years.
●Pain occurs primarily in the lower extremities. Upper-extremity pain can occur in conjunction with lower-extremity pain.
●Pain is often bilateral and located deep in the legs, usually the thigh, calf, popliteal fossa, or shin.
●Pain is paroxysmal and may be severe.
●In older children (6 to 12 years), the pain may be described as crampy, a creeping sensation, or restless legs.
●Pain occurs primarily in the evening or nighttime hours and may interrupt sleep. It usually resolves by morning, but some patients have isolated daytime complaints. Daytime complaints rarely limit usual activities.
●Pain is relieved by massage, heat, or first-order analgesics, such as acetaminophen or ibuprofen.
●Normal patterns of activity are maintained.
●The physical examination during and after the episodes is normal.
●Associated complaints of recurrent abdominal pain and/or headaches occur in approximately one-third of patients.
●A family history of growing pains or rheumatic complaints is common.
●The pains are chronic but episodic, typically occurring at least once a week, with an overall duration that often may last years and persist into adolescence. However, symptom-free periods of days, weeks, or months may occur between episodes.
DIAGNOSIS — The diagnosis of growing pains is one of exclusion. Thus, clinicians should have considered and ruled out as necessary other causes of limb pain that may need additional evaluation and/or treatment before making the diagnosis. The diagnosis can usually be made clinically in a child with a typical presentation who remains pain free during the day, is otherwise healthy, and has a normal general physical and musculoskeletal exam. It is not necessary to perform radiographs or laboratory tests to make the diagnosis in these children. (See 'Evaluation' below.)
Features associated with growing pains that suggest the diagnosis include [2,32]:
●Pain typically occurs late in the day or awakens the child.
●Pain is not specifically related to the joints.
●Pain occurs at least monthly for at least three months.
●Pain is intermittent, with symptom-free periods of at least days.
●Pain may be accentuated by increased activity during the day.
●The physical examination is normal.
●Ancillary studies, if performed, are normal.
DIFFERENTIAL DIAGNOSIS — The differential diagnosis of intermittent lower-extremity pain is extensive (table 1). It is important to exclude conditions that may require additional evaluation, therapy, or monitoring. Patients with growing pains have a normal physical exam, no constitutional symptoms, and generally no limitation of activities, which differentiates growing pains from other conditions in the differential diagnosis. Thus, most of these disorders can be excluded on the basis of history and physical examination. Laboratory studies and/or radiographs may be necessary in others. (See 'Evaluation' below.)
These conditions include:
●Trauma (particularly stress fractures due to overuse) – Key features of stress fractures and other overuse syndromes include a history of localized pain of insidious onset that increases with activity and focal tenderness limited to the stress fracture or overuse site. (See "Overview of stress fractures".)
●Bone tumors and leukemia – Bone tumors may be the most difficult to distinguish from growing pains without additional studies because tumor pain often occurs at night. The pain associated with primary bone tumors, such as Ewing sarcoma or osteoid osteomas, typically begins as intermittent pain and increases in severity over the course of time. The pain associated with Ewing sarcoma, though, may disappear spontaneously for weeks or months at a time. In contrast to growing pains that are most commonly bilateral, the bone pain associated with tumors is unilateral. Patients with bone tumors also may have a palpable mass. On physical examination, children with bone tumors may experience tenderness with compression of the bone and/or soft tissue, which is not seen in children with growing pains. (See "Clinical presentation, staging, and prognostic factors of Ewing sarcoma" and "Nonmalignant bone lesions in children and adolescents", section on 'Osteoid osteoma'.)
Children with leukemia usually have systemic symptoms, such as fever, pallor, or weight loss, which are absent in children with growing pains. (See "Overview of common presenting signs and symptoms of childhood cancer".)
●Infection (particularly if partially treated with antibiotics) – The initial symptoms of hematogenous osteomyelitis can be nonspecific in children of all ages (eg, low-grade fever, malaise, irritability, decreased appetite or activity). Once the infection becomes established in bone, symptoms are more localized, with focal findings of bone inflammation (warmth, swelling, point tenderness) and limitation of function (eg, limp, limited use of extremity). (See "Hematogenous osteomyelitis in children: Clinical features and complications" and "Hematogenous osteomyelitis in children: Evaluation and diagnosis".)
●Osteonecrosis (eg, Legg-Calvé-Perthes disease [LCP]) – LCP is a syndrome of idiopathic osteonecrosis (avascular necrosis) of the hip. It typically presents as insidious onset of mild hip pain (including pain with activity) and/or limp with a Trendelenburg gait. (See "Approach to hip pain in childhood", section on 'Legg-Calvé-Perthes and secondary avascular necrosis'.)
●Metabolic disorders (eg, rickets) – Rickets refers to the changes at the growth plate caused by deficient mineralization of bone and occurs before the closure of the growth plates. The skeletal findings are similar for calcipenic and phosphopenic rickets and may include delayed closure of the fontanelles, parietal and frontal bossing, enlargement of the costochondral junction ("rachitic rosary"), widening of the wrist, and lateral bowing of the femur and tibia (bow legs). Typical radiographic findings and an elevated serum alkaline phosphatase can help confirm the diagnosis. (See "Overview of rickets in children".)
●Sickle cell disease – Pain in sickle cell disease (SCD) can occur acutely due to veno-occlusive disease or chronically due to bone and joint damage, central sensitization, and other factors. The sites of acute pain can include the back, chest, extremities, and abdomen. In young children, sickle cell dactylitis (acute, painful swelling in the hands or feet, also known as hand-foot syndrome) may be the most common complaint. (See "Overview of the clinical manifestations of sickle cell disease" and "Diagnosis of sickle cell disorders".)
●Rheumatologic disorders, including nonsystemic categories of juvenile idiopathic arthritis (JIA) – Children with nonsystemic categories of JIA may present with a limp and/or pain and inflammation of one or more joints. Systemic manifestations (other than uveitis) are characteristically absent. (See "Oligoarticular juvenile idiopathic arthritis" and "Polyarticular juvenile idiopathic arthritis: Clinical manifestations, diagnosis, and complications".)
EVALUATION — The evaluation of children who complain of recurrent, self-limited lower-extremity pain should include a complete history and physical examination.
History — The history should characterize the pain episodes and include the following questions (see 'Clinical features' above):
●How often does it occur?
●Where does it occur? Is it bilateral or unilateral? Is the pain localized or diffuse?
●When does it occur?
●What triggers the pain (eg, activity)?
●How long does it last?
●What makes it better?
●Is there the complaint of pain in the night (or naps) or during the day?
●Does the pain affect the child's gait, activity, sleep, or school attendance?
●Are there any associated signs or symptoms (eg, fever, swelling, erythema, malaise, weight loss)?
●Does the child have recurrent headaches or abdominal pain?
●Is there a history of recent illness (eg, viral infection, group A streptococcal infection)?
●Has there been a recent increase or change in type of exercise or sports activity?
●Is there a family history of medical problems (eg, sickle cell anemia, metabolic disease, rheumatologic disorders)?
●Is there a family history of growing pains?
●Is there a history of preterm birth or intrauterine growth restriction?
●Is there adequate intake of calcium and vitamin D?
●Is there exercise intolerance, more than expected muscle fatigue with exertion, or history of rhabdomyolysis (suggests a metabolic myopathy)?
In addition, it is important to determine whether there are psychosocial factors contributing to the symptoms. Additional questions such as the following may be helpful:
●What are the current stressors facing the patient and caregiver(s)?
●Do the episodes of pain correlate temporally with events that the child may wish to avoid?
●Who might benefit if the pain prevented some activity?
Physical examination — The physical examination must be carefully performed to exclude other conditions in the differential diagnosis (table 1).
●Abnormalities on the musculoskeletal examination (eg, genu valgum, overpronation of the foot, generalized hypermobility, decreased range of motion, joint swelling, or elicited tenderness upon bone compression) may indicate orthopedic or rheumatologic conditions (eg, juvenile idiopathic arthritis [JIA]).
●Skin rashes are sometimes present in children with rheumatologic disease or infection (eg, dermatomyositis, systemic lupus erythematosus, psoriasis, or syphilis).
●The neurologic examination, including gait, may be abnormal in children with spinal cord tumors. An abnormal gait may also be seen in a variety of musculoskeletal disorders but should not be present in a child with growing pains. (See "Evaluation of the child with a limp".)
●Lymphadenopathy or splenomegaly should prompt consideration of malignancy, infection, or rheumatic disease.
Further evaluation for concerning findings — Additional evaluation may be necessary to exclude more serious conditions in the differential diagnosis and usually is warranted in all children who have [30,33,34]:
●Systemic symptoms (eg, unexplained fever, weight loss, decreased activity)
●Persistent, increasing, or unilateral limb pain
●Pain during the day
●Limp or limitation of activities
●Localized findings on examination (decreased range of motion, warmth, tenderness, swelling, erythema)
●Pain that is isolated to the upper extremity, back, or groin
The additional evaluation may include, but is not limited to, complete blood count (CBC) and differential, erythrocyte sedimentation rate (ESR) or C-reactive protein (CSR), vitamin D level, and/or plain radiographs. Abnormal results in any of these tests exclude a diagnosis of growing pains.
Pediatricians, family practitioners, pediatric orthopedic surgeons, and pediatric rheumatologists were surveyed regarding the diagnostic evaluation of a child with typical growing pains [34]. Depending upon the specialty, between 19 and 51 percent of clinicians would order CBC and differential, between 30 and 58 percent would order an ESR, and 37 to 52 percent would order radiographs. Diagnostic tests were more likely to be ordered if the patient was >12 years of age or if the clinician felt the need to reassure the parents/caregivers.
While parental/caregiver concern is not always a reliable indicator of disease, it is easily assessed during the office visit. When parents/caregivers seem particularly concerned and difficult to reassure, thorough diagnostic evaluation may be a way to both exclude a significant underlying problem and provide the necessary reassurance. However, the evaluation must be clinically appropriate since there is potentially no limit to the concerns that caregivers may express or the studies they may request. In addition, there is the possibility of a false-positive result that leads to additional unnecessary testing. Clinicians who are confident of their diagnosis can usually reassure caregivers of the appropriateness of their recommendations even without an extensive diagnostic evaluation. Scheduling a follow-up visit for reassessment may help caregivers needing additional reassurance.
TREATMENT — Little is written about the treatment of growing pains in children, and few controlled trials have been performed. The management must include recognition of the child's pain and its effects on his or her functioning [35]. Education of the patient and caregiver(s) is a crucial component of the management plan. An understanding of the benign nature of the disorder may alleviate unnecessary concern, fear, and suffering [36].
Acute pain relief may be achieved with massage, over-the-counter analgesics (eg, acetaminophen or ibuprofen), and heat in various forms. Often, episodes that awaken the child at night cluster in groups of nights and follow days of increased physical activity. In a child who has been appropriately evaluated, acetaminophen or ibuprofen given at bedtime may prevent awakening following a day of increased activities or break the cycle of repeated complaints. At times, a longer-acting analgesic given after dinner, such as naproxen, may be necessary for the child to sleep through the night.
Patients found to have low vitamin D levels should receive vitamin D and calcium supplements.
Caregivers should encourage the child to continue usual childhood activities and social experiences [32]. Discontinuation of normal activities does not prevent growing pains and may in fact make the pain a focus for the child and caregiver(s).
Muscle stretching exercises may relieve chronic symptoms. In one unblinded study of 36 children with growing pains, children who were treated with a muscle stretching regimen (table 2) had more rapid resolution of their symptoms than controls (children who participated in the stretching regimen had an average of zero episodes per month by nine months, while children in the control group continued to have one to two episodes per month at the end of the 18-month observation period) [11]. However, it is not clear whether the improvement was a result of the exercise or the increased caregiver attention required for the twice-daily routine.
Children with hypermobility, foot malalignment, genu valgum, and/or poor balance ability may benefit from physical therapy and/or foot orthoses [23].
In general, clinical follow-up is not needed. However, children who have pain that increases in frequency or severity may require additional evaluation. (See 'Further evaluation for concerning findings' above.)
SUMMARY AND RECOMMENDATIONS
●Definition – Growing pains are defined as pain awakening a child at night (or from naps) in the absence of any objective manifestations of musculoskeletal abnormalities and generally without any limitations of activity. Although growing pains are a common musculoskeletal condition, occurring in approximately 15 percent of children, their etiology is not known. (See 'Definition' above and 'Epidemiology' above and 'Etiology' above.)
●Diagnosis – The diagnosis can usually be made clinically in a child with a typical presentation who remains pain free during the day and is otherwise healthy. However, it is important that a complete history and physical are performed to differentiate growing pains from other, more serious conditions. (See 'Diagnosis' above and 'Differential diagnosis' above and 'History' above and 'Physical examination' above.)
●Additional evaluation and differential diagnosis – The differential diagnosis of intermittent lower-extremity pain is extensive (table 1). If the child appears ill, complains of pain during the day or with activity, or if pain worsens or persists, the diagnosis is unlikely to be growing pains. A thorough evaluation (eg, complete blood count [CBC] and differential, erythrocyte sedimentation rate [ESR] or C-reactive protein [CRP], and/or plain radiographs) is required in children who meet any of these conditions. Abnormal results in any of these tests exclude a diagnosis of growing pains. (See 'Differential diagnosis' above and 'Further evaluation for concerning findings' above.)
●Management – Treatment is usually symptomatic and must include education and reassurance. (See 'Treatment' above.)
ACKNOWLEDGMENT — The UpToDate editorial staff acknowledges Thomas JA Lehman, MD and Sarah Ringold, MD, MS, who contributed to earlier versions of this topic review.
