Short stature refers to a child whose height is ≥2 standard deviations below the mean for sex and age and may be a normal growth variant or secondary to underlying disease. Normal variants of growth failure include:

• Familial short stature – Low-normal growth velocity throughout life with normal bone age.
• Constitutional growth delay – Results in childhood short stature, as children grow at a low-normal rate but have normal adult height. Puberty is typically delayed, with bone age correlating to height age.
• Idiopathic short stature – Height below 2 standard deviations of the mean for age and sex without identifiable underlying cause.

In addition, there are several pathologic causes of growth failure including:

• Undernutrition – Low height-for-weight with inadequate caloric intake.
• Glucocorticoid therapy – Causes decreased growth via interference of endogenous growth hormone secretion and bone formation. Catch-up growth may occur with cessation of steroids.
• Gastrointestinal (GI) disease – Decreased height velocity before the onset of GI symptoms (Crohn disease, ulcerative colitis, Celiac disease) and are often underweight for height.
• Renal disease – Growth failure is seen in 1/3 children with renal disease due to dietary restrictions, anorexia, uremia, metabolic acidosis, or use of steroids for treatment.
• Rheumatologic disease – Conditions, especially juvenile idiopathic arthritis, are associated with growth failure thought to be secondary to inflammatory cytokines and corticosteroid therapy.
• Genetic causes – Turner syndrome, Noonan syndrome, Prader-Willi syndrome, Russell-Silver syndrome, and various skeletal dysplasias lead to short stature.
• Endocrine diseases – Characterized by excess weight-for-height and may be secondary to Cushing syndrome, hypothyroidism, or growth hormone deficiency.
• Cancer – Poor growth can be seen during treatment for cancer due to negative side effects of chemotherapy, although catch-up growth may be seen once therapy is completed. Late effects of cranial radiation therapy may be seen due to hypothalamic damage.