What it is (overview)

An XR Bone Age Hand test is a type of diagnostic imaging that uses a small amount of X-ray radiation to take a picture of the left hand and wrist. The image is used to estimate a child’s bone age, also called skeletal maturity. Bone age reflects how far a child’s bones have developed compared with typical development for their chronological (calendar) age.

During childhood and adolescence, the bones in the hand and wrist contain growth areas called growth plates. As a child grows, these growth plates change in a predictable pattern and eventually “close” when growth is complete. A radiologist compares the X-ray to standardized reference images (often using methods such as Greulich and Pyle) to estimate bone age.

What the results mean in plain language:

If the reported bone age is about the same as the child’s actual age, skeletal development is generally on track. If the bone age is younger than the child’s age (also called “delayed bone age”), it can suggest slower skeletal development, which may be seen with some growth patterns, chronic illness, or certain hormonal conditions. If the bone age is older than the child’s age (“advanced bone age”), it can suggest faster-than-expected skeletal development, which may be linked to early puberty or hormone-related conditions. Bone age is not a diagnosis by itself—your clinician interprets it together with height, growth rate, puberty stage, family history, and lab tests (often hormone testing) to understand the cause and guide next steps.

When & why it's usually done

Doctors most often order an XR Bone Age Hand as part of a pediatric assessment when there are concerns about a child’s growth or pubertal development. It helps determine whether growth is happening earlier, later, or at a typical pace, and can help estimate remaining growth potential.

This test is commonly done when a child has:

Growth concerns such as being much shorter or taller than expected for age, crossing growth percentiles on a growth chart, or a noticeably slow or rapid growth rate.

Early or delayed puberty, including signs of puberty that start unusually early (for example, breast development or testicular enlargement earlier than expected) or puberty that seems late or not progressing.

Possible hormonal imbalance, such as suspected thyroid problems, growth hormone deficiency, excess cortisol, or excess sex hormones, where bone age can provide clues about how hormones are affecting bone development.

Medical conditions that can affect bone health and growth, including long-term inflammatory disease, malnutrition, chronic kidney disease, or conditions requiring long-term steroid use.

Treatment planning and monitoring, such as evaluating response to growth hormone therapy, monitoring puberty suppression or induction therapy, or helping specialists make decisions about timing of certain orthopedic or endocrine interventions.

Parents often worry about safety. A hand and wrist X-ray uses a low radiation dose, and the area imaged is small. The test is quick, non-invasive, and typically does not require special preparation.

Common diseases related to it

• Constitutional delay of growth and puberty
• Precocious (early) puberty
• Delayed puberty
• Growth hormone deficiency
• Idiopathic short stature
• Hypothyroidism
• Hyperthyroidism
• Cushing syndrome (excess cortisol) or long-term glucocorticoid exposure
• Congenital adrenal hyperplasia (CAH)
• Turner syndrome
• Chronic kidney disease (renal osteodystrophy affecting bone development)
• Chronic malnutrition or malabsorption (including celiac disease)

Health goals where it may help

• Evaluating a child’s growth pattern and identifying potential growth disorders early
• Assessing skeletal maturity to estimate remaining growth and expected adult height range (as part of a broader evaluation)
• Supporting hormonal imbalance workups (thyroid, adrenal, and puberty-related concerns) alongside lab testing
• Monitoring response to treatments that affect growth (e.g., growth hormone therapy or puberty-related therapies)
• Tracking bone health in children with chronic illnesses or long-term medication use that may impact growth plates
• Helping guide specialist decisions in pediatric endocrinology and orthopedic care when growth timing matters