What is a growth disorder?

A growth disorder is any type of problem in infants, children, or teenagers that prevents normal growth. Normal growth depends upon several factors, such as nutrition, genetics, and hormones (chemical messengers of the body) (see Anatomy of the Endocrine System). Hormones are necessary for normal growth and development; they regulate the body's growth, metabolism (the physical and chemical processes of the body), and sexual development and function.

Endocrine (hormonal) causes of growth disorders include thyroid hormone deficiency (hypothyroidism), growth hormone deficiency, hypopituitarism, or other hormone disorders. However, some growth problems are not necessarily growth disorders; normal variants of growth patterns include genetic short height (familial short stature) and slow growth/delayed puberty (constitutional growth delay).

Although growth hormone was originally used to treat growth hormone deficiency (this group of patients respond the best to growth hormone therapy), there have been other conditions for which growth hormone therapy has been approved for use. These include Turner syndrome, chronic renal insufficiency, Prader-Willi syndrome, and children who were small for gestational age and have not caught up in their growth by the age of two years. In 2003 the FDA approved the use of growth hormone for children who have "Idiopathic Short Stature," that is, children who are quite short (more than 2.25 SD below the mean in height), and who are unlikely to have an adult stature in the normal range.