Growth hormone deficiency type of dwarfism: This type of dwarfism is caused by congenital abnormalities in the pituitary structure or secretion function of the hypothalamus, or reduced pituitary function due to traumatic brain injury, tumor, radiation injury, etc., which results in insufficient secretion of growth hormone. In this type of dwarf patients, the diagnosis can be confirmed by growth hormone stimulation test. Generally, a value of <5μg/L in the growth hormone stimulation test is a complete growth hormone deficiency, and a value between 5-10μg/L is a partial growth spurt deficiency. Treatment: For children with growth hormone deficiency, it is safest and most effective to give them exogenous growth hormone supplementation because their bodies are inherently deficient in growth hormone. Idiopathic dwarfism: It is one of the most common causes of dwarfism in children, and the affected children are completely normal except for their dwarfism. Therefore, idiopathic dwarfism must be diagnosed only after all causes of dwarfism have been ruled out. Treatment: In July 2003, the FDA (Food and Drug Administration, a worldwide authoritative drug regulatory organization) approved the long-term treatment of idiopathic dwarfism (i.e., unexplained dwarfism) with growth hormone. From the two large clinical trials they have done, it appears that growth hormone is safe and effective in the treatment of idiopathic dwarfism. Intrauterine growth retardation (IUGR) or small for gestational age (SGA): Intrauterine growth retardation is caused by abnormalities during pregnancy. The height and weight at birth are significantly smaller than normal. Most children with intrauterine growth retardation can catch up with normal infants within 6-12 months after birth, and later the growth and development is similar to that of normal infants of the same age. However, about 10-30% of children with intrauterine growth retardation do not show catch-up growth. Treatment: In 2001, the NFDA (Food and Drug Administration) approved growth hormone treatment for IUGR, and children with IUGR who have been short in stature should be treated with growth hormone after the age of 2.