By: Jennifer Arnold, MD, MSc, FAAP
Short stature means a child is much shorter than most children the same age and sex. Doctors commonly use this term when a child’s height falls below the third percentile on a growth chart.
While many children with short stature are perfectly healthy and growing normally, some growth patterns may suggest an underlying medical condition. By monitoring growth over time, pediatricians can make sure children are growing as expected and identify any concerns early.
What is a growth chart?
A growth chart is a tool pediatricians use to track a child's growth over time. It shows how a child’s height compares with other children of the same age and sex. Each line represents a percentile. For example, if a boy’s height is at the 25th percentile, about 25 out of 100 boys his age are shorter than he is.
Most children do not follow these lines exactly, but most often, their growth over time tracks near these lines, often following their specific growth curve. A child whose height falls below the third percentile line has short stature compared with other children of the same age.
How do doctors check your child’s growth?
During routine checkups, pediatricians carefully measure growth and compare the findings with standardized growth charts.
- For children from birth to age 2, the doctor measures head circumference (distance around the widest area of the head), weight and length.
- For children ages 2 to 19, the doctor checks weight, height and body-mass index (BMI).
The American Academy of Pediatrics recommends doctors use the World Health Organization (WHO) growth charts from birth to 2 years of age and the CDC charts from age 2 to 19.
Tracking growth over time is key. One measurement alone does not tell the full story.
When is a child’s growth pattern not typical?
Your pediatrician will look at many things when assessing your child's growth. The height of each parent can tell them how tall their child is likely to be when fully grown. A child whose parents have below-average height will most likely grow up to have a below-average height too.
The rate of growth, called "growth velocity," is also important. A child who is not growing at the same rate as other children of the same age will slowly drop further down on the growth curve as they get older. For example, they might cross from the 25th percentile line to the fifth percentile line. Crossing percentile lines on the growth curve like that can be a sign of an underlying medical condition affecting growth and should be evaluated by your pediatrician.
What causes short stature in children?
If your child seems shorter than other kids the same age, it’s natural to wonder why. While slower growth can sometimes point to a health concern, most children with short stature are healthy and growing—just on the shorter side.
When short stature is part of normal growth
There are several common reasons for short stature that are not related to medical concerns:
Familial short stature: This is when one or both parents are shorter than average. Their child grows at a normal rate and is healthy but is also likely to be shorter as an adult.
Constitutional delay in growth and puberty: This is when a child grows more slowly and may be shorter than other kids their age during childhood. Puberty starts later than usual, giving the child more time to grow. Most children in this group experience "catch up growth" and reach a typical adult height.
Idiopathic short stature: This means there is no known cause for the child’s shorter height, but they are healthy and growing.
Are there medical conditions that can affect a child’s growth?
Short stature may occasionally be a sign that a child does have an underlying health condition, but there are usually other symptoms that make it clear something else is going on.
Medical conditions that can affect growth include:
- Chronic medical conditions that affect major organs: These include heart disease, asthma, celiac disease, inflammatory bowel disease, kidney disease, anemia and bone disorders. Children being treated for cancer or recovering from chemotherapy may also have slower growth. Hormonal (endocrine) conditions such as hypothyroidism, growth hormone deficiency or diabetes that has been difficult to manage, can affect how a child grows.
- Cushing syndrome: This happens when the body makes too much cortisol (a stress hormone) or from long-term use of high-dose steroid medications.
- Genetic conditions: Down syndrome, Turner syndrome, Silver-Russell syndrome, Noonan syndrome and skeletal dysplasia can affect growth.
- Poor nutrition (malnutrition). Not getting enough calories, protein or other important nutrients can slow a child's growth and typically affect weight gain and then height over time.
- Babies who were born small for their gestational age (how far along a pregnancy is) or had intrauterine growth restriction (something limiting growth) during pregnancy might be smaller as they grow.
- Medications: Stimulant medicines to treat attention-deficit/hyperactivity disorder (ADHD) and inhaled corticosteroids used for asthma could slow growth in some children.
What are skeletal dysplasias and how can they affect height?
Skeletal dysplasias are a group of genetic conditions affecting bone growth and development.
Achondroplasia and hypochondroplasia
Achondroplasia and hypochondroplasia are two types of skeletal dysplasia that can be an underlying cause of short stature. Both disorders affect bone growth in the arms and legs by stopping cartilage from turning into bone.
Achondroplasia is the most common type of skeletal dysplasia resulting in short stature. Children with achondroplasia usually have short arms and legs and a larger head size, while their torsos are closer to average size. Children with achondroplasia can also experience back and neck problems, spinal curvature, frequent ear infections and hearing problems and breathing problems.
Achondroplasia does not usually affect a child’s ability to think or learn. Most children with achondroplasia have typical intelligence and development, although some may reach physical milestones on a different timeline.
Osteogenesis imperfecta
Other genetic bone disorders that can lead to short stature include osteogenesis imperfecta (also called brittle bone disease), which causes bone weakness.
What tests are used to assess children for short stature?
The most important "test" is to monitor your child's growth over time using the growth chart. Your child’s pediatrician will follow their growth over time using growth charts throughout childhood. If there are concerns about short stature, looking at growth over about 6 months is often the most helpful way to understand your child’s growth pattern. If your child is growing as expected, no further testing may be needed.
Bone age X-ray
In addition, your child's doctor may order a bone age X-ray, usually of the left hand and wrist. This helps show whether bones are maturing slower, faster or as expected. It can also help determine whether puberty or growth may be happening earlier or later, and provide clues about future growth and adult height.
Blood tests
Blood tests are not always needed if a child is short but healthy and growing at a steady rate. For example, some children stay on a lower growth line over time. But if your child is below the third percentile or is growing more slowly than expected, the doctor may suggest blood tests to look for health conditions that could affect growth.
When should parents be concerned about their child's growth?
Talk with your pediatrician if:
Your child is much shorter than other children their age
Growth seems to be slowing
Your child drops to lower percentiles on the growth chart over time
Puberty starts much later than expected
Your child has other symptoms, such as low energy or poor appetite
You have any other questions about your child’s growth
Remember
Regular checkups help monitor your child’s growth over time. Most children with short stature are healthy and growing normally. If there are concerns about your child's growth pattern, your pediatrician can determine whether additional testing or referral to a pediatric endocrinologist is needed.
About Dr. Arnold
 Jennifer Arnold, MD, MSc, FAAP, is a pediatrician, neonatologist, medical educator and disability health advocate at Boston Children’s Hospital and Harvard Medical School. She serves as Executive Director of Immersive Design Systems at Boston Children’s and is the Medical Director for Skeletal Dysplasia in the hospital’s Skeletal Health Center. Her clinical and academic work spans skeletal dysplasia, neonatology, disability health equity, healthcare simulation, patient safety and innovative approaches to improving the patient and family experience.
Dr. Arnold brings a unique perspective to her work as both a physician and a person with skeletal dysplasia. She is passionate about advancing equitable, person- and family-centered care for children with disabilities and ensuring that patients and families have access to accurate, balanced, and practical health information. An internationally recognized speaker, educator, advocate and New York Times bestselling author, Dr. Arnold is also the host of Boston Children’s Hospital’s Answers Parentcast, where she helps translate pediatric health information for patients and families. She has dedicated much of her career and public-facing work to improving pediatric healthcare, advancing disability inclusion and empowering patients and families to be active participants in their care.
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