growth hormone deficiency

Growth hormone deficiency is too little growth hormone, and in a child its hallmark is slow growth: the height curve flattens and the child gradually drifts below peers. It is the mirror image of gigantism, an under-fueled rather than over-fueled growth engine.

The deficiency can be congenital, from genetic defects or pituitary malformation, or acquired, from a tumor near the pituitary, surgery, radiation, head injury, or inflammation. Sometimes only growth hormone is missing; sometimes it is part of broader hypopituitarism affecting several pituitary hormones at once.

In children the clinical clue is a poor growth velocity and short stature with otherwise normal body proportions, often with a young-looking face and delayed bone age. Because growth hormone is secreted in pulses, diagnosis usually requires stimulation tests, supported by a low IGF-1.

An important note for completeness: growth hormone matters in adults too. After childhood it still influences body composition, bone density, muscle, and lipids, so adult-onset deficiency causes more fat, less muscle, and reduced wellbeing rather than short stature. Treatment in both cases is replacement with recombinant human growth hormone, dosed to the situation.