Dwarfism occurs when an individual person or animal is short in stature resulting from a medical condition caused by slow growth. In humans, dwarfism is sometimes defined as an adult height of less than 4 feet 10 inches (58 in; 147 cm). Dwarfism can be caused by more than 300 distinct medical conditions, such that the symptoms and characteristics of individuals with dwarfism vary greatly. Disproportionate dwarfism is characterized by one or more body parts being relatively large or small in comparison to those of an average-sized adult, with growth variations in specific areas being apparent. In cases of proportionate dwarfism, the body appears normally proportioned, but is unusually small.
There is no single treatment for dwarfism. Individual differences, such as bone growth disorders, sometimes can be treated through surgery, some hormone disorders can be treated through medication, and by hormone replacement therapy; this treatment must be done before the child's growth plates fuse. Individual accommodations, such as specialized furniture, are often used by people with dwarfism. Many support groups provide services to aid individuals with dwarfism and the discrimination they may face because of their dwarfism.
For people, in addition to the medical aspect of the condition, there are social and sociological aspects as well. For a person with dwarfism, heightism can lead to ridicule in childhood and discrimination in adulthood. In the United Kingdom, United States, Canada, Australia, and other English-speaking countries, some people with dwarfism prefer to be called little people.
Historically, the term midget was used to describe "proportionate dwarfs"; however, this term is now regarded as offensive and pejorative (see Terminology). Another definition for midget is any thing (especially an animal) that is small in proportion to a typical specimen. Hypotonia, or low muscle tone, is common in dwarfs, but intelligence and lifespan are usually normal. Defining dwarfism by height alone is problematic because short stature in itself is not a disorder. For example, pygmies have adult male heights of less than 150 cm (4 feet 11 inches) on average.