Lipodystrophy is a medical condition characterized by abnormal or degernative conditions of the body's fat tissue. ("Lipo" is Latin for "fat" and "dystrophy" is Latin for "abnormal or degenerative condition".)
A lipodystrophy can be a lump or small dent in the skin that forms when a person keeps performing injections in the same spot. These types of lipodystrophies are harmless. People who want to avoid them can do so by changing (rotating) the places where they perform injections. For diabetics, using purified insulins may also help.
Other lipodystropies manifest as the excess or lack of fat in various regions of the body. These include but are not limited to having sunken cheeks, "humps" on the back or back of the neck. They are often seen as a symptom of AIDS. They can be caused by medibolic abnormalities due to genetic issues such as Syndrome-X or side-effects from medications such as antiretroviral drugs.