Human height

Human height or stature is the distance from the bottom of the feet to the top of the head in a human body, standing erect. It is measured using a stadiometer, in centimetres when using the metric system or SI system, or feet and inches when using United States customary units or the imperial system.

In the early phase of anthropometric research history, questions about height measuring techniques for measuring nutritional status often concerned genetic differences.

Height is also important because it is closely correlated with other health components, such as life expectancy. Studies show that there is a correlation between small stature and a longer life expectancy. Individuals of small stature are also more likely to have lower blood pressure and are less likely to acquire cancer. The University of Hawaii has found that the "longevity gene" FOXO3 that reduces the effects of aging is more commonly found in individuals of small body size. Short stature decreases the risk of venous insufficiency.

When populations share genetic backgrounds and environmental factors, average height is frequently characteristic within the group. Exceptional height variation (around 20% deviation from average) within such a population is sometimes due to gigantism or dwarfism, which are medical conditions caused by specific genes or endocrine abnormalities.

The development of human height can serve as an indicator of two key welfare components, namely nutritional quality and health. In regions of poverty or warfare, environmental factors like chronic malnutrition during childhood or adolescence may result in delayed growth and/or marked reductions in adult stature even without the presence of any of these medical conditions.

The study of height is known as auxology.

Growth has long been recognized as a measure of the health of individuals, hence part of the reasoning for the use of growth charts. For individuals, as indicators of health problems, growth trends are tracked for significant deviations, and growth is also monitored for significant deficiency from genetic expectations. Genetics is a major factor in determining the height of individuals, though it is far less influential regarding differences among populations. Average height is relevant to the measurement of the health and wellness standard of living and quality of life of populations.

Humans grow fastest (other than in the womb) as infants and toddlers, rapidly declining from a maximum at birth to roughly age 2, tapering to a slowly declining rate, and then, during the pubertal growth spurt (with an average girl starting her puberty and pubertal growth spurt at 10 years and an average boy starting his puberty and pubertal growth spurt at 12 years), a rapid rise to a second maximum (at around 11−12 years for an average female, and 13−14 years for an average male), followed by a steady decline to zero. The average female growth speed trails off to zero at about 15 or 16 years, whereas the average male curve continues for approximately 3 more years, going to zero at about 18−19, although there is limited research to suggest minor height growth after the age of 19 in males. These are also critical periods where stressors such as malnutrition (or even severe child neglect) have the greatest effect.