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Short stature refers to a height of a human being which is below typical. Whether a person is considered short depends on the context. Because of the lack of preciseness, there is often disagreement about the degree of shortness that should be called ''short''. In a medical context, short stature is typically defined as an adult height that is more than two standard deviations below the mean for age and gender, which corresponds to the shortest 2.3% of individuals. In developed countries, this typically includes adult men who are shorter than tall and adult women who are shorter than tall. Again though, when shortness is called "short" is debatable, others would say and for men and women respectively due to those heights being one standard deviation below the average for each of their genders, while others would say for men and for women since both heights are three standard deviations below the average for their respective genders. In either of those cases, by comparison, the median or typical adult height in these populations (as the widely abundant statistics from these countries clearly state) is about for men and for women. ==Causes== Shortness in children and young adults nearly always results from below-average growth in childhood, while shortness in older adults usually results from loss of height due to kyphosis of the spine or collapsed vertebrae from osteoporosis. From a medical perspective, severe shortness can be a variation of normal, resulting from the interplay of multiple familial genes. It can also be due to one or more of many abnormal conditions, such as chronic (prolonged) hormone deficiency, malnutrition, disease of a major organ system, mistreatment, treatment with certain drugs, chromosomal deletions, inherited diseases, birth defect syndromes, bone structures fusing earlier than intended or many other causes. Human Growth Hormone (HGH) deficiency may occur at any time during infancy or childhood, with the most obvious sign being a noticeable slowing of growth. The deficiency may be genetic. Among children without growth hormone deficiency, short stature may be caused by Turner syndrome, chronic renal insufficiency, being small for gestational age at birth, Prader–Willi syndrome, or other conditions. When the cause is unknown, it is called ''idiopathic short stature''. Short stature can also be caused by the bone plates fusing at an earlier age than normal, therefore stunting growth. Normally, your bone age is the same as your biological age but for some people, it is older. For many people with advanced bone ages, they hit a growth spurt early on which propels them to average height but stop growing at an earlier age. However in some cases, people who are naturally shorter combined with their advanced bone age, end up being even shorter than the height they normally would have been because of their stunted growth. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Short stature」の詳細全文を読む スポンサード リンク
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