Growth Spurts and Height Prediction: What Decides How Tall a Child Will Be

A ten-year-old’s jeans fit in September. By November the hems are hovering an inch above the ankle, and the kid who used to glide through doorways has started clipping the frame with a shoulder. Every parent recognizes the scene. What is new, as of June 2025, is the online conversation around it.

Short videos promising to “maximize” a teenager’s growth spurts have been racking up views, pushing stretching routines, sleep hacks, supplement stacks and, more worryingly, injectable “research peptides” sold outside any approved medical channel. Searches for growth spurts and height prediction have climbed with them, and so have the questions landing in pediatric clinics: Is my child on track? Can we tell how tall they will be? Can anything move the number?

The evidence is clearer and calmer than the feed suggests. Here is what actually decides height, how doctors estimate it, and which signs deserve a proper appointment.

What changed recently in growth spurts and height prediction

The science of measuring children has moved in steps, not leaps. The foundation is still the World Health Organization’s Child Growth Standards, published in 2006 after tracking roughly 8,500 healthy, breastfed children in Brazil, Ghana, India, Norway, Oman and the United States. That study established something that still matters: well-nourished children grow in remarkably similar patterns everywhere in the world, regardless of ethnicity, for the first five years of life.

In 2010 the CDC recommended that US clinicians use the WHO charts for children under 24 months and the CDC’s own 2000 growth charts from age 2 onward. In December 2022 the CDC added extended BMI-for-age charts so that doctors could plot children with very high body mass index values accurately rather than off the top of the page. None of that changed how height itself is tracked, but it reflects a steady push toward measuring every child against a reference that fits.

What has changed fastest is the culture around the numbers. Growth-tracking apps now put percentiles in a parent’s pocket, and social platforms have turned the ordinary teenage growth spurt into an optimization project. Posts routinely cite stretching, hanging from bars, specific foods or unapproved injectables as ways to add inches. There is no randomized trial behind any of those claims, and the injectables in question are not approved for use in healthy children. The growth charts have not changed; the anxiety has.

That gap, between a stable body of evidence and a noisy feed, is the reason this piece exists. The rest of it walks through the biology first, the prediction tools second, and the myths last, so the corrections make sense rather than sounding like scolding.

How growth spurts actually work: hormones and growth plates

Children do not get taller from the middle of their bones. They get taller from the ends. Near each end of a long bone sits a growth plate, a thin layer of cartilage where new cells form, line up like stacked coins, and are gradually replaced by bone. That slow conveyor belt is what turns a two-foot newborn into a six-foot adult.

The speed of the conveyor is set by hormones. Growth hormone, released by the pituitary gland in pulses, mostly during deep sleep, signals the liver and the growth plates to produce insulin-like growth factor 1, a messenger that tells cartilage cells to multiply. Thyroid hormone keeps the whole system running at the right tempo. Then puberty adds the accelerant: estrogen in girls and testosterone in boys (part of which the body converts into estrogen) sharply increase growth-plate activity for a couple of years.

Estrogen has a second job that explains why growth stops. In higher amounts it matures the growth plate until the cartilage is fully replaced by bone, a process called epiphyseal fusion. Once a plate fuses, that bone can no longer lengthen. This typically happens between ages 14 and 16 in girls and 16 and 18 in boys, which is why a closed growth plate on an X-ray is the definitive sign that growing is finished, whatever a supplement label claims.

A growth spurt, then, is simply a window when these signals are turned up. The first-year spurt is driven mainly by nutrition and growth hormone; the pubertal spurt is driven by sex hormones layered on top. Understanding that sequence makes most of the rest of this topic, including why timing varies so much between children, fall into place.

The growth spurt timeline from birth to adulthood

Children do not grow at a steady rate, and the pattern is more predictable than most parents expect. A typical baby adds around 25 cm (10 inches) in the first year, roughly doubling in length by age 4 or 5. Growth then slows to a long, quiet plateau through the elementary-school years before puberty lights it up again. The table below summarizes the usual pace; individual children vary, and a steady curve matters more than any single number.

Stage	Typical height gain	What is driving it
Birth to 12 months	About 25 cm (10 in) over the year	Nutrition, growth hormone, catch-up or catch-down to genetic track
12 to 24 months	About 12 cm (5 in)	Growth hormone; rate halves as infancy ends
2 to 4 years	About 7–8 cm (3 in) per year	Growth hormone, thyroid hormone
4 years to start of puberty	About 5–6 cm (2–2.5 in) per year	Steady hormonal baseline; slowest phase of childhood
Puberty, girls (peak around age 11–12)	Up to 8 cm (3 in) in the peak year; roughly 20–25 cm total	Estrogen layered on growth hormone
Puberty, boys (peak around age 13–14)	Up to 9–10 cm (4 in) in the peak year; roughly 25–30 cm total	Testosterone, converted partly to estrogen
After peak velocity	Slows to zero over 2–3 years	Growth plates fuse under rising estrogen

Two details from this table surprise people. First, the infant year is the biggest growth spurt a human ever has; nothing in adolescence matches a 50 percent increase in length. Second, the mid-childhood plateau is normal, not a warning sign. A six-year-old growing a little over two inches a year is doing exactly what the charts expect.

What age do kids have the biggest growth spurt?

If the question means fastest growth, the answer is the first year of life. If it means the spurt parents notice and worry about, it is puberty, and the age depends heavily on sex and on individual timing.

Girls usually begin puberty between 8 and 13, with breast budding as the first visible sign. Their peak growth velocity arrives early in the sequence, typically around age 11 to 12, often before the first menstrual period. After menarche, growth continues for about two more years but slows markedly; most girls add only another 5 to 7 cm (2 to 3 inches) from that point.

Boys start later, between 9 and 14, with testicular enlargement as the first sign. Their peak velocity comes later in the sequence as well, around 13 to 14, and it is faster than girls’ peak. Those two facts, a later start and a longer run of childhood growth before the spurt, account for most of the average adult height difference of roughly 13 cm (5 inches) between men and women.

The spread around those averages is wide and still normal. Two healthy 13-year-old boys can sit a foot apart in height simply because one is at peak velocity and the other has not started. Pediatric guidance from the NHS and Mayo Clinic draws the line for medical evaluation not at being shorter than friends, but at puberty beginning before age 8 in girls or 9 in boys, or showing no signs by 13 in girls or 14 in boys.

Timing also runs in families. A parent who was the last to grow in high school is more likely to have a child on the same schedule, and those children usually catch up fully.

How to tell if your child is having a growth spurt

The most reliable sign is boring: a tape measure. Measuring height every three to six months on the same wall, shoes off, heels against the baseboard, and writing it down gives a far better picture than any single clue. A spurt shows up as a jump in centimeters per year, not as a feeling.

That said, the everyday signs are real, and they cluster:

• Appetite climbs sharply, sometimes for weeks, as the body demands energy and protein for new tissue.
• Sleep needs increase; growth hormone is released in pulses during deep sleep, and teenagers mid-spurt often sleep longer and more heavily.
• Shoe size moves before height. Feet and hands tend to grow first in adolescence, which is part of why the proportions look briefly off.
• Clothes stop fitting in length before width, and trouser hems are the usual giveaway.
• Mild, aching leg pain in the evening is common in younger children, though it does not track growth rate as neatly as the name “growing pains” implies.
• Mood and energy can swing, especially in puberty, when the same hormones driving growth are reshaping the brain’s reward and sleep systems.

In babies, growth spurts often announce themselves as a few days of cluster feeding and fussiness, commonly around 2 to 3 weeks, 6 weeks, 3 months and 6 months. Those windows are rough patterns from pediatric experience rather than fixed events, and a baby who feeds more for a few days then settles is behaving normally.

What a growth spurt does not look like is a sudden change in proportion, persistent pain in one joint, or growth that stalls. Those belong in the clinic, and the section on when to see a doctor covers them in detail.

Height prediction: the mid-parental height formula and its limits

The simplest height prediction tool is also the one pediatricians use at nearly every well-child visit. It is called mid-parental height, and it uses nothing more than the parents’ heights.

For a boy: add the mother’s height and the father’s height, add 13 cm (5 inches), and divide by two. For a girl: add both heights, subtract 13 cm (5 inches), and divide by two. The 13 cm adjustment accounts for the average difference between adult men and women. The result is the child’s estimated adult height, sometimes called the target height.

Now the honest part. That number sits in the middle of a range, and the range is wide: roughly plus or minus 8.5 cm, or about 3.5 inches either way, captures around 95 percent of children. A boy with a target of 178 cm (5 ft 10 in) could reasonably end up anywhere from 170 cm to 186 cm. Parents who read the midpoint as a promise are setting up disappointment or needless worry.

Why so wide? Each child inherits a different shuffle of the thousands of gene variants that influence height, and both parents may have been shorter or taller than their own genetic potential because of their childhood nutrition or illness. The formula knows none of that.

What the target height is genuinely good for is context. If a child is tracking along the 25th percentile and the mid-parental estimate also lands around the 25th percentile, the picture is consistent and reassuring. If the child is on the 3rd percentile with parents at the 75th, that mismatch is one of the things that prompts a closer look.

Bone age and other clinical height prediction tools

When a pediatrician wants more precision than a parental average, the next step is usually a bone age X-ray: a single image of the left hand and wrist. Bone age is a measure of how mature a child’s skeleton is, judged by comparing the shape and fusion of the small bones against a standard atlas. A child can have a chronological age of 12 and a bone age of 10, meaning there is more growing time left than the calendar suggests, or a bone age of 14, meaning growth plates are closer to fusing.

Bone age feeds into formal prediction methods, the best known being the Bayley-Pinneau tables, which combine current height, chronological age and bone age to estimate adult stature. These methods were developed decades ago on specific populations and still carry a margin of error of several centimeters, especially in children with very early or very late puberty. They are useful for answering “how much growth is likely still to come,” not for pinning down a final number.

The other tool is the growth chart itself, which doctors read for velocity rather than position. A child who holds a steady percentile curve year after year is almost always growing normally, whatever that percentile is. A child who crosses two major percentile lines downward over a year or two, or whose growth rate drops below about 4 cm per year between age 4 and puberty, is the one who triggers blood tests for thyroid function, celiac disease, growth hormone pathways and other treatable causes.

A popular rule of thumb, that adult height is about double a child’s height at age 2, is a rough historical observation rather than a clinical tool. It lands in the right neighborhood for many children and misses badly for early and late bloomers.

What decides how tall a child will be: genes versus environment

Large twin and family studies put the heritability of adult height at around 80 percent in well-nourished populations. That figure describes how much of the height variation between people in a population is explained by genetic differences, not how much of any one person’s height came from their parents. It is still the single most important number in this topic, because it means the ceiling is largely set before birth.

Height is not controlled by one gene but by thousands of common variants, each nudging the result by a fraction of a millimeter. Genome-wide studies have identified well over ten thousand such variants, which is why two siblings with identical parents can differ by several inches: they drew different hands from the same deck.

The remaining 20 percent is where environment acts, and it acts mainly in one direction. Chronic undernutrition, repeated infections, celiac disease, inflammatory bowel disease, untreated hypothyroidism, severe asthma requiring long courses of oral steroids, and significant long-term stress can all keep a child from reaching their genetic ceiling. The WHO standards demonstrated this plainly: children of every ethnic background who were adequately fed and healthy grew along the same curves.

The reverse does not hold. Extra calories, extra protein, extra calcium or extra sleep beyond what a healthy child needs do not raise the ceiling. Overnutrition does speed up childhood growth and advances bone age, so a heavier child may be taller than peers at 9, but the growth plates also fuse earlier and adult height typically ends up where the genes pointed.

Population height has risen roughly 10 cm in many countries over the past century, which proves environment matters at scale. Within a single well-fed family, though, the genes do most of the deciding.

Nutrition, sleep and growth spurts: what actually matters

Because environment can only subtract from genetic potential, the practical goal is simple: remove the subtractions. For most children in high-income countries, that means ordinary balanced eating and adequate sleep, not special protocols.

Three nutrients deserve attention during growth spurts. Protein supplies the raw material for new bone matrix and muscle, and a varied diet with dairy, eggs, legumes, fish or meat covers it for nearly all children without supplements. Calcium is the mineral that gives bone its density; the NIH Office of Dietary Supplements notes that recommended intakes rise in the 9-to-18 age band precisely because the skeleton is laying down close to half its lifetime bone mass in those years. Vitamin D allows the gut to absorb that calcium, and deficiency is common in children with limited sun exposure, darker skin, or little fortified food in the diet. Severe deficiency causes rickets, which can genuinely impair growth; mild deficiency mainly affects bone strength rather than height.

Sleep matters for a mechanistic reason. The largest pulses of growth hormone occur during slow-wave sleep in the first hours of the night. The CDC’s referenced guidance recommends 9 to 12 hours for children aged 6 to 12 and 8 to 10 hours for teenagers. Chronic short sleep is linked in observational studies to poorer growth and higher body weight, though evidence that extra sleep beyond those ranges adds height is absent.

Iron and zinc deficiency can also slow growth and are worth checking in restrictive eaters. What does not help: protein powders in a child who already eats enough, megadose vitamins, or any product marketed as a “height supplement.” There is no randomized trial showing any over-the-counter product increases adult height in a well-nourished child.

Do growth spurts make kids clumsy?

Yes, sometimes, and the explanation is more interesting than the stereotype. During the adolescent spurt, limbs lengthen faster than the brain’s internal map of where those limbs are. The sensory system that tracks body position, called proprioception, has to recalibrate for arms that are suddenly two inches longer and a center of gravity that has shifted. Until it does, a teenager may misjudge doorframes, knock over glasses or trip on familiar stairs.

Research on this “adolescent awkwardness” is real but modest. Longitudinal studies of motor skills in boys and girls have found a temporary dip in coordination in a subset of adolescents around the time of peak height velocity, lasting a few months and resolving on its own. The effect is not universal, is small on average, and comes from observational cohorts rather than controlled trials. So the honest grade is: plausible mechanism, consistent but limited observational support.

Growing pains are a related complaint with a misleading name. They are aching, cramping pains in the thighs, calves or behind the knees, typically in the evening or at night, in children aged roughly 3 to 12, and they affect both legs. Mayo Clinic notes that despite the name, there is no good evidence that they are caused by growth itself; they are more likely linked to daytime activity and perhaps lower pain thresholds. They never cause limping, swelling, redness or pain in a single joint, and they are gone by morning.

Two practical notes. First, rapid growth does slightly raise the risk of certain overuse injuries in active teenagers, because growth plates are temporarily weaker than the tendons pulling on them. Second, a sudden change in gait, persistent pain on one side, or clumsiness that is getting worse rather than fading is not a growth spurt and needs assessment.

My baby's head is growing faster than their body: is that normal?

Usually, yes. Babies are built top-heavy on purpose. At birth the head accounts for about a quarter of total body length, and head circumference averages around 35 cm. In the first year it grows by roughly 12 cm, a pace the body cannot match proportionally. The reason is the brain, which reaches about 80 percent of its adult volume by age 2. Head growth is essentially brain growth, and it front-loads.

Pediatricians therefore plot three separate curves at every infant visit: length, weight and head circumference. The three do not need to sit on the same percentile. A baby on the 40th percentile for length and the 75th for head circumference is common and typically reflects family head size; large heads, like height, run in families.

What clinicians watch is the trajectory. A head circumference that holds its percentile, even a high one, is reassuring. A head that crosses two major percentile lines upward over a few months is the finding that prompts further evaluation, because it can occasionally signal fluid building up around the brain or, rarely, other structural causes. The soft spot on the top of the skull, the anterior fontanelle, is a useful bedside clue; it normally closes between about 9 and 18 months, and while it is open it should feel soft and flat when the baby is calm and upright, not bulging or tense.

Red flags that should prompt a same-day call rather than waiting for the next checkup include a bulging fontanelle, repeated forceful vomiting, unusual sleepiness or irritability, eyes that seem fixed downward, or a head that visibly enlarges over weeks. In the absence of those signs, a head that is simply ahead of the body is a healthy baby doing what babies do.

What the evidence actually says, and how strong it is

Medical claims are not all equal, and a topic this crowded with confident online advice needs its evidence sorted by strength. Here is a graded summary.

Strong, consistent evidence (large cohort studies, twin studies, international standards): adult height is around 80 percent heritable in well-nourished populations; healthy children of all ethnicities grow along the same curves in early childhood; puberty timing drives the age of the adolescent spurt; growth plates fuse under estrogen and growth then stops permanently; chronic undernutrition and untreated chronic disease reduce adult height.

Moderate evidence (randomized trials in specific diagnosed conditions): prescription growth hormone (somatropin) increases adult height in children with growth hormone deficiency and in several other approved conditions, with gains that vary widely between individuals and depend on starting early. In idiopathic short stature, trials show an average gain of a few centimeters, with some children gaining little. These are clinical decisions for a pediatric endocrinologist, not general height tools.

Limited or observational evidence: the temporary coordination dip around peak height velocity; the link between short sleep and poorer growth; the role of specific nutrient deficiencies like zinc in slowing growth in otherwise well-fed children.

Expert opinion or extrapolation: the specific ages quoted for infant growth spurts (3 weeks, 6 weeks, 3 months); the idea that growing pains are caused by growth itself (Mayo Clinic notes they probably are not).

No credible evidence: that stretching, hanging, posture devices, specific foods, protein powders, vitamin megadoses, or any over-the-counter “height” supplement increases adult height in a healthy child. No randomized trial supports these, and the mechanism is implausible once growth plates are understood.

The pattern is clear. The things that decide height have strong evidence and are mostly out of anyone’s control. The things marketed as controllable have essentially none.

Common myths about growth spurts and getting taller

Most viral height advice fails for the same reason: it ignores the growth plate. Once that is understood, the myths unravel quickly.

“Stretching or hanging from a bar adds inches.” Hanging briefly decompresses the discs between vertebrae, which is why people are about a centimeter taller in the morning than at night. The effect reverses within hours. No exercise lengthens bone.

“Coffee stunts growth.” This traces to decades-old concern that caffeine might reduce calcium absorption. Studies in adolescents have not found caffeine reduces height. Caffeine can disrupt sleep, which is a better reason to limit it in children.

“Lifting weights closes growth plates early.” There is no evidence that supervised, age-appropriate strength training harms growth. Growth-plate injuries happen, but from acute trauma and overuse, not from training itself.

“A big growth spurt means a tall adult.” A child who shoots up early often finishes early too; bone age advances along with height. Late bloomers frequently end up taller than the classmates who towered over them at 12.

“Eating more makes kids taller.” Excess calories accelerate childhood growth and bone maturation but do not raise adult height. Undereating can reduce it; overeating cannot increase it.

“Supplements can reopen growth plates.” Fused growth plates are bone. No oral product changes that.

“Research peptides boost growth hormone naturally and safely.” These are unapproved substances sold outside medical supervision, with no safety data in children and no evidence of any effect on adult height. The next section explains their status plainly.

One myth runs the other way and deserves correcting too: that being shorter than peers means something is wrong. Half of all healthy children are below the 50th percentile by definition. Steady growth along any curve is the reassuring sign.

Growth hormone, peptides and height: the regulatory facts

Because the online trend has blurred the line between medicine and marketing, it helps to state the regulatory picture plainly.

Recombinant human growth hormone, known generically as somatropin, is a prescription medicine approved by the US Food and Drug Administration for specific childhood conditions: growth hormone deficiency, Turner syndrome, chronic kidney disease, Prader-Willi syndrome, children born small for gestational age who do not catch up, and, since 2003, idiopathic short stature below a defined threshold. It is given by injection under the care of a pediatric endocrinologist, with regular monitoring of growth, bone age, blood sugar and other markers. Whether a particular child is a candidate, and what to expect, is entirely a decision for that specialist, informed by testing.

Somatropin is not approved to make a healthy child of average height taller, and there is no evidence it would do so. Using it that way would be off-label, and no mainstream guideline supports it.

Products marketed online as “research peptides,” sometimes described as growth hormone secretagogues or releasing factors, sit in a different category altogether. They are not FDA-approved medicines for any use in children. Many are sold with disclaimers that they are “not for human consumption,” which places them outside the quality, sterility and dosing controls that apply to real medicines. There are no clinical trials showing they increase adult height, and no safety data in growing children. They are not for sale as medicines and not for self-use, and a family considering anything in this space should bring the question to a pediatrician rather than a seller.

A parent who has already been offered a prescribed medicine for growth should never adjust or stop it based on something read online; that conversation belongs with the prescribing clinician.

When to see a doctor about growth spurts or height

Most children never need a growth evaluation beyond routine checkups. These are the findings that should move a family from watching to asking.

Growth rate and chart findings

• Height crossing two major percentile lines downward over 12 to 24 months, or a growth rate below about 4 cm (1.5 inches) per year between age 4 and the start of puberty.
• Height far below the range predicted by the parents’ heights, especially with any other symptom.
• A sudden, unexplained acceleration in growth in a child under 8 or 9, which can accompany early puberty.
• Head circumference in an infant crossing percentile lines upward, or a bulging, tense soft spot.

Puberty timing

• Breast development before age 8 in a girl, or testicular enlargement, pubic hair or a deepening voice before age 9 in a boy.
• No breast development by 13 or no menstrual period by 15 in a girl; no testicular enlargement by 14 in a boy.

Symptoms that are not growth spurts

• Persistent pain in one joint or one leg, limping, swelling, warmth or redness, or pain that is present in the morning.
• Clumsiness that worsens over weeks, loss of previously mastered skills, severe headaches, or vision changes.
• Unexplained weight loss, chronic diarrhea, ongoing fatigue, or a child who stops gaining weight along with height.
• A visibly curved spine, uneven shoulders or a rib hump noticed during a growth spurt; scoliosis most often progresses during peak growth.

For any of these, the first stop is the child’s regular pediatrician or family doctor, who can measure accurately, review the chart, order basic tests and refer to a pediatric endocrinologist if needed. Any decision about testing, imaging or treatment rests with that clinician. A clear growth record brought to the appointment, even a pencil line on a door frame with dates, makes the visit far more useful.

Frequently asked questions

How do you tell if a child is having a growth spurt?

The clearest sign is a measured jump in height over a few months, so a dated mark on a wall beats any instinct. Everyday clues that cluster together include a surge in appetite, longer and deeper sleep, shoes becoming tight before trousers do, hems rising, mild evening leg aches in younger children, and a brief spell of clumsiness in teenagers as coordination catches up with longer limbs.

What age do kids have the biggest growth spurt?

In absolute terms, the first year of life, when babies grow about 25 cm. The adolescent spurt that parents notice peaks around age 11 to 12 in girls and 13 to 14 in boys, with boys growing slightly faster at peak. A difference of a year or two either side of those ages is normal, and timing tends to follow the family pattern.

How accurate is height prediction from parents' heights?

Only moderately. The mid-parental formula gives a midpoint, but about 95 percent of children finish within roughly 8.5 cm (3.5 inches) above or below it, a range of seven inches in total. It is best used to check whether a child’s current percentile fits the family, not to forecast a final number. Bone age X-rays narrow the estimate somewhat but still carry an error of several centimeters.

Do growth spurts make kids clumsy?

Often, briefly. During peak growth the limbs lengthen faster than the brain updates its internal map of the body, and observational studies show a temporary dip in coordination in some adolescents that resolves within months. Clumsiness that is getting worse, affects one side, or comes with headaches, vision changes or lost skills is not a growth spurt and should be assessed by a doctor.

My baby's head is growing faster than their body. Is this normal?

Usually, yes. Head growth in infancy is brain growth, and the brain reaches about 80 percent of adult size by age 2, so the head naturally leads. Pediatricians plot head circumference on its own curve and care about trajectory, not whether it matches body percentiles. A head crossing percentile lines upward, a bulging soft spot, repeated vomiting or unusual sleepiness warrant a prompt call.

Can a child still grow after puberty ends?

Only until the growth plates fuse, which happens under the influence of estrogen roughly two years after a girl’s first period and by about 16 to 18 in boys. After that, bones cannot lengthen, though the spine can gain a few millimeters of posture-related height into the early twenties. An X-ray of the hand showing closed growth plates is the definitive sign that growing is complete.

Does sleep affect growth spurts?

Yes, through a real mechanism: the largest pulses of growth hormone are released during deep sleep early in the night. Children aged 6 to 12 are advised to get 9 to 12 hours and teenagers 8 to 10. Chronic short sleep is linked in observational studies to poorer growth, but there is no evidence that sleeping beyond the recommended range adds height to a healthy child.

Can nutrition or supplements make a child taller?

Adequate nutrition lets a child reach their genetic potential; extra nutrition does not raise it. Deficiencies in protein, calcium, vitamin D, iron or zinc can slow growth and are worth correcting with a clinician’s guidance. No over-the-counter height supplement has randomized-trial evidence of increasing adult height, and overfeeding tends to speed up bone maturation without changing the final result.

Why is my late-blooming teenager shorter than everyone else?

Most often because their growth spurt simply has not arrived. A pattern called constitutional delay of growth and puberty, which runs in families, means a child grows steadily but starts puberty later, then catches up and usually reaches the height their genes predicted. A doctor can confirm this with a growth chart review and a bone age X-ray, which typically shows the skeleton is younger than the calendar.

When should a child's height be checked by a doctor?

When growth falls below about 4 cm a year in mid-childhood, drops across two major percentile lines, or sits far below what the parents’ heights predict; when puberty starts before 8 in girls or 9 in boys, or has not started by 13 and 14 respectively; or when height concerns come with pain in one joint, weight loss, fatigue, a curved spine or other symptoms. The pediatrician decides on any tests or referral.

References

• CDC: Growth Charts
• WHO: Child Growth Standards
• MedlinePlus: Growth Disorders
• NHS: Stages of puberty: what happens to boys and girls

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.