Why do children grow taller—and why does it eventually stop?
The secret lies deep in our bones. Specifically, in the long bones of the legs and arms, which grow in length thanks to a remarkable tissue called the growth plate. Understanding how these structures work can help parents better support their child’s development—and protect it from harm.
What Is Longitudinal Bone Growth?
Children’s height increases because their bones get longer, not thicker. This process—called longitudinal bone growth—occurs at both ends of long bones, in a thin layer of cartilage known as the growth plate.
A long bone in a child has four main parts:
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Diaphysis: the shaft or main middle section where bone forms first
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Metaphysis: the flared area next to the shaft where growth occurs
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Physis (Growth Plate): a thin layer of cartilage between the metaphysis and epiphysis where new bone is produced, allowing the bone to lengthen
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Epiphysis: the rounded end of the bone, responsible for secondary bone formation
Source：The Royal Children's Hospital Melbourne
Within the growth plate, specialized cells called chondrocytes go through a cycle:
they multiply, enlarge, then get replaced by bone tissue in a process called endochondral ossification. As long as this cycle continues, the bone can keep lengthening—and the child keeps growing taller.
Once the growth plates close—typically in late puberty—this process ends. The epiphysis and diaphysis fuse into a single solid bone, and height gain stops permanently.
What Controls How Fast Bones Grow?
Bone growth may seem automatic, but it’s tightly regulated by hormones, nutrients, and mechanical signals.
Hormonal Signals
Growth hormone (GH), released primarily during deep sleep, stimulates the liver to produce IGF-1 (Insulin-like Growth Factor 1)—a key growth factor that activates chondrocytes in the growth plates, driving bone elongation.
Sex hormones like estrogen and testosterone also influence this process, particularly during puberty, when growth accelerates and then gradually slows as the plates begin to close.
While most growth-support approaches focus on nutrition or hormone injection, iKids-Growth, a science-backed supplement based on natural extracts, is formulated to amplify body's own growth signals by supporting bone and muscle function assosiated with IGF-1 activity. Rather than increasing hormone levels directly, its goal is to help the body respond more effectively to internal growth signals, especially during the critical years when growth plates are still open and active.
For a deep dive into GH–IGF-1 signaling and bone growth, see Bone Growth
Nutrition and Minerals
Bones need building blocks: protein for collagen structure, calcium and phosphorus for mineralization, and zinc, magnesium, and vitamin D to support metabolism and growth factor activity. Malnutrition can suppress growth even when growth plates are open.
Physical Activity
Weight-bearing and impact exercises (like jumping or running) apply mechanical stress, which helps stimulate bone cell activity and mineral density. Children who are active often have stronger, healthier bones. Read more: Frontiers in Bioengineering – Mechanical Stress on Bone Growth
Together, these systems determine how long—and how well—bone growth continues. But there’s another piece that’s often overlooked: injury.
How Injuries Can Disrupt Bone Growth
While many focus on how to stimulate bone growth, it’s equally important to avoid disrupting it. And one of the biggest threats? Growth plate fractures.
Because growth plates are made of softer cartilage, they are weaker than surrounding bone—making them more vulnerable to trauma. Falls, collisions, and sports injuries can all result in fractures that cross or damage the plate.
According to pediatric data, 15–30% of all bone fractures in children involve a growth plate. If improperly treated, they can lead to:
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Premature closure, stopping growth early
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Uneven bone development, leading to limb length differences
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Deformity or angulation in weight-bearing bones
Fortunately, with early diagnosis and appropriate orthopedic care, most children recover fully. Still, these injuries highlight how important it is to not only promote growth—but also protect it. See Mayo Clinic: Growth plate fractures - Symptoms and causes
Still have questions about your child’s height growth?
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FAQ
Q1: Can stretching exercises help bones grow longer?
No. While stretching improves posture and flexibility, it doesn't influence bone growth. Only internal processes in the growth plate lengthen bones.
Q2: What age do growth plates close?
It varies, but typically between ages 14–16 in girls and 16–18 in boys. After closure, bones can no longer grow in length.
Q3: Can growth resume after a bone fracture near the growth plate?
Yes—if treated early and correctly. But delayed treatment can lead to complications like growth arrest or asymmetry.
