Causes of Growing Pains
The causes of Growing Pains remain somewhat unclear, but research suggests a combination of mechanical, neurological, and possibly psychological factors. Despite the name, the causes of Growing Pains are not directly linked to growth spurts or bone development. Instead, the discomfort is thought to originate in muscles, tendons, or ligaments, often in relation to physical activity or fatigue.
Growing Pains are classified as a type of benign nocturnal limb pain of childhood. While no structural abnormality is found in affected children, several theories help explain why some children experience these recurring episodes.
1. Muscle Fatigue
One of the most widely accepted explanations is muscle overuse. Children who are very active during the day may strain their:
Calf muscles
Hamstrings
Quadriceps
This leads to microtrauma and delayed-onset muscle soreness (DOMS)—similar to what adults feel after intense exercise. The muscles tire and may tighten in the evening, triggering cramping or aching at night.
2. Poor Biomechanics
Children with poor lower limb alignment may be more prone to discomfort. Some possible biomechanical contributors include:
Flat feet or overpronation
Hypermobile joints
Knock knees or bow-legged postures
Uneven gait or limb length discrepancy
These conditions increase the load on certain muscle groups, potentially causing repetitive strain.
Podiatrists often assess foot posture and gait in children with frequent leg aches. In some cases, orthotics or supportive footwear may help alleviate the strain.
3. Growth-Related Stretching of Tissues
Although the name “Growing Pains” suggests a link to physical growth, the evidence is weak. That said, during periods of rapid growth, children’s bones lengthen faster than muscles and tendons can adapt. This may cause:
Tension on the muscle attachments
Reduced flexibility, especially in the hamstrings or calves
Mild inflammation of connective tissue
This stretching may lead to sensations of tightness or soreness, particularly in children who are already active or have limited flexibility.
4. Pain Perception and Sensitivity
Another possible contributor is heightened pain sensitivity. Some children with Growing Pains may have:
Lower pain thresholds
Increased sensitivity to minor injuries or muscle use
Family histories of migraines or fibromyalgia
This theory aligns with observations that children with Growing Pains are more likely to report other pain conditions and may experience abdominal pain, headaches, or recurrent fatigue.
5. Emotional and Psychological Factors
There is growing recognition that stress, anxiety, and emotional distress may amplify or trigger musculoskeletal pain. Children may not always express emotional discomfort in words but may instead “feel” it physically.
Examples include:
School stress or social changes
Separation anxiety
Major life transitions (e.g. moving house, new sibling)
While not the cause per se, emotional strain may act as a pain amplifier or influence how children cope with physical sensations.
6. Genetic Predisposition
Growing Pains often run in families. A parent or sibling may recall experiencing similar leg aches in childhood. This suggests a genetic or familial tendency, possibly related to:
Joint flexibility
Pain sensitivity
Foot posture or gait mechanics
7. Inflammatory Theories (Disproven)
Older theories once proposed that inflammation in the growth plates caused pain. However, imaging and biopsy studies have shown no signs of inflammation or damage in the growth areas of affected children. This supports the conclusion that Growing Pains are not linked to inflammation, arthritis, or structural disease.
Summary of Theories
| Possible Cause | Explanation |
| Muscle fatigue | Overuse during the day leads to pain at night |
| Poor biomechanics | Foot or leg alignment issues cause strain |
| Growth-related stretching | Rapid bone growth may outpace muscle flexibility |
| Pain sensitivity | Some children may feel pain more intensely |
| Emotional stress | Stress and anxiety may contribute to or magnify pain perception |
| Family history | Genetic traits influence muscle tone or joint mobility |
Risk Factors That May Increase Susceptibility
High physical activity levels
Poor flexibility or tight muscles
Sleep disturbances
Anxiety or fear of being alone at night
Sedentary days followed by sudden bursts of activity
While not direct causes, these factors may create a setting in which Growing Pains are more likely to occur or worsen.
What the Evidence Tells Us
No single cause explains all cases of Growing Pains. It’s likely that a combination of physical, genetic, and emotional factors contribute to their development. Importantly, the absence of any serious pathology reassures families that while inconvenient, these pains are benign.
Conclusion | Causes of Growing Pains
The causes of Growing Pains are multifactorial and not directly related to bone growth, despite the name. Muscle overuse, poor biomechanics, emotional stress, and individual sensitivity all likely play a role. Understanding the causes of Growing Pains helps caregivers and healthcare providers provide reassurance, avoid unnecessary tests, and focus on practical ways to reduce discomfort and support the child’s wellbeing.
