Hemimelia is a birth defect consisting in unilateral or bilateral underdevelopment of the distal part of the lower or upper limb.

[1] The affected bone may be shortened or not develop at all.

[2][3] Transverse hemimelia is a congenital absence of part or all of a limb (including hand or foot) and is called amelia when the entire limb is missing.

[2][4] Paraxial hemimelia means partial absence of one of the elements of the limb in the longitudinal axis (in phocomelia there is no complete absence of a part of the limb).

[2] Sub types of hemimelia are the following: