The most frequently diagnosed cause of short stature is achondroplasia, a genetic condition that results in disproportionately short arms and legs.

Dwarfism is a condition in which a person, animal or plant is much below the ordinary size of the species.

When applied to people, it implies not just extreme shortness, but a degree of disproportion. Dwarfism is now rarely used as a medical term and is sometimes (but not always) considered impolite or pejorative. Today, the term little person tends to be preferred.

According to and organization called Little People of America the human definition of this term is stated as such "a medical or genetic condition that usually results in an adult height of 4'10" or shorter, among both men and women, although in some cases a person with a dwarfing condition may be slightly taller than that."

The average height of an adult with dwarfism is 4'0, but typical heights range from 2'8 to 4'8.

Relatively common genetic conditions that result in disproportionate short stature include:

• achondroplasia (one per 26,000 to 40,000 births)
• spondyloepiphyseal dysplasia congenita (SEDc), (one per 95,000 births)
• diastrophic dysplasia (one per 110,000 births)
• pseudoachondroplasia
• hypochondroplasia
• osteogenesis imperfecta (OI).

The most frequently diagnosed cause of short stature is achondroplasia, a genetic condition that results in disproportionately short arms and legs. The average height of adults with achondroplasia is 4'0". Although achondroplasia accounts for perhaps 70 percent of all cases of dwarfism, there are over 200 diagnosed types, and there are some individuals with dwarfism who never receive a definitive diagnosis and/or have a condition that is unique to themselves or their family.

As one might expect from their names, pseudoachondroplasia and hypochondroplasia are conditions that have been confused with achondroplasia; diastrophic dysplasia occasionally is, too. OI is characterized by fragile bones that fracture easily.

Proportionate dwarfism -- short-stature conditions that result in the arms, legs, trunk, and head being in the same proportion (relative size to one another) as in an average-size person -- is often the result of a hormonal deficiency, and may be treated medically, resulting in an average or near average height. There are not such treatments available for people with disproportionate short stature.

Famous people with dwarfism

• Jason Acuña, Wee-Man US actor
• Michael J. Anderson, US actor
• Kenny Baker, actor who portrayed R2-D2
• Billy Barty, US actor
• Bushwick Bill, US musician, founding member of Geto Boys
• Sebastiano Biavati, 17th century curator of museum of curiosities
• Joseph Boruwlaski, Polish "count"
• Joe C., Kid Rock's sidekick
• Caroline Crachami, Sicilian dwarf
• Warwick Davis, UK actor
• Peter Dinklage, US actor
• Meredith Eaton, US actor
• The Doll Family, German-born siblings
• Josh Ryan Evans, US actor
• Nicholas Feny. French-born court dwarf
• Charles Flato, American writer and Soviet spy, he was also hunchbacked
• Phil Fondacaro, US Actor
• Eddie Gaedel, made one plate appearance for the St. Louis Browns in 1951
• Jeffrey Hudson, English court dwarf and jester to Charles I
• Martin Klebba, US actor
• Wybrand Lolkes, Dutch dwarf
• George Washington Morrison Nutt, "Commodore Nutt"
• Alexander Pope, poet
• Meinhardt Raabe, oldest surviving munchkin from "The Wizard of Oz"
• David Rappaport, UK & US actor
• Judy-Lynn del Rey, US science fiction editor
• Timothy Roman, the son of US actress Susan Cabot
• Zelda Rubinstein, US actress
• Felix Silla, US actor
• Charles Proteus Steinmetz, scientist and engineer
• Charles Sherwood Stratton, "General Tom Thumb"
• Verne Troyer, US actor
• Hervé Villechaize, French-born actor
• Lavinia Warren, US
• Chick Webb, big band drummer