To be officially classified as having dwarfism, individuals must have a maximum height of 4 feet, 10 inches. Although a height just under 5 feet is the cutoff for classification of dwarfism, the average height for individuals of short stature is 4 feet. In many instances, the terms "dwarves" and "little people" are used interchangeably.
Although some people are born with dwarfism because of a random genetic error, most inherit the gene for short stature from one or both of their biological parents. Both men and women are affected by dwarfism, and reach full-grown adult heights of 2 feet, 8 inches to 4 feet, 8 inches. Although some people born with this gene are proportionate in physical build, many have a concurrent condition called achrondroplasia. Achrondoplasia is a genetic condition that produces shortened arms and legs. Although most dwarves are affected by achrondoplasia, other genetic conditions can produce a shortened stature as well. In addition to genetics, short stature may be caused by other factors, such as hormonal levels. Dwarfism caused by hormonal deficiency can often be corrected through medical treatments. When treated, affected individuals may ultimately reach an adult height closer to that of average humans.