Short stature refers to a height of a human 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. Dwarfism is the condition of being very short, often caused by a medical condition.
In a medical context, short stature is typically defined as an adult height that is more than two standard deviations below a population’s mean for age and gender, which corresponds to the shortest 2.3% of individuals in that population. The median or typical adult height in developed countries 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. The most common causes of short stature in childhood are constitutional growth delay or familial short stature.
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) growth hormone or thyroid hormone deficiency, malnutrition, disease of a major organ system, mistreatment, treatment with certain drugs, chromosomal deletions. 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 or Noonan syndrome, chronic kidney disease, being small for gestational age at birth, Prader–Willi syndrome, Wiedemann-Steiner syndrome, or other conditions. Genetic skeletal dysplasias also known as osteochondrodysplasia usually manifest in short-limbed disproportionate short stature.
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, the bone age is the same as the 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.
Some of the reasons growth development may slow include: Genetics. When a child’s parents and grandparents are short, the child may also be short; this is known as familial short stature. Also, the target height is merely an estimate and some children simply don't grow as tall as expected. Genetic conditions. Several genetic syndromes can lead to short stature, including Prader-Willi syndrome, Turner syndrome and Noonan syndrome. Chronic diseases. Growth hormone is produced by the pituitary gland, located in the middle of the brain. Therefore, chronic medical problems that affect the pituitary gland may also affect growth. For example, radiation to the brain can affect pituitary function, so pediatric cancer or its treatment can lead to short stature. Gastrointestinal diseases that impair nutrition, such as inflammatory bowel disease and celiac can affect growth, can also be a cause. Many other conditions can also delay the growth rate, including hypothyroidism, heart disease, kidney disease, immunological disease and several other endocrine disorders. Growth hormone deficiency. Some children simply don't produce enough growth hormone, including those born with a poorly developed pituitary gland. Malnutrition. This is caused by an inadequate food supply, an eating disorder, or an underlying condition or treatment that affects appetite, lack of nourishment is a common cause of growth delay. Psychosocial stress. Exposure to violence because of war or famine or just being in a home environment that’s not very nurturing, children can also experience a psychosocial stress that keeps them from growing properly,” Dr. Patel says. “That can be reversed just by removing them from the stressful environment.”