Dwarfism describes a condition in which an organism is exceptionally small, and is mostly found in the animal kingdom. In humans, it is sometimes defined as being less than 147 centimeters (4 ft 10 in) tall as an adult, regardless of gender; the average height of adults with dwarfism is 122 centimeters (4 ft 0 in), although some people with dwarfism are slightly taller. Disproportionate dwarfism is characterized by either short limbs or a short torso. In cases of proportional dwarfism, both the limbs and the trunk are unusually small. Intelligence is usually normal, and most of them have near-normal life spans.

People with dwarfism can usually have children, although there are additional risks for mother and child depending on the underlying condition. The most common and recognizable form of dwarfism in humans (accounting for 70% of cases) is achondroplasia, a genetic disorder that causes the limbs to become miniaturized. Growth hormone deficiency is the cause of most other cases. Treatment depends on the underlying cause. People with genetic disorders can sometimes be treated with surgery or physical therapy. Hormonal disorders can also be treated with growth hormone therapy before the baby’s growth plates fuse.

Individual fixtures, such as specialized furniture, are often used by people with dwarfism. A variety of support groups provide services to help individuals and the discrimination they may face. In addition to the medical aspect of the disease, there are social aspects. For a person with dwarfism, height discrimination can lead to ridicule in childhood and discrimination in adulthood.

In the United Kingdom, the United States, Canada, Australia, and other English-speaking countries, labels taken by some people with dwarfism include dwarf (plural: dwarfs), small person (LP), or person of short stature. Historically, the term dwarf has been used to describe dwarfs (primarily proportional ones); however, the term is now often regarded as offensive.