Hemihyperplasia (sometimes referred to as hemihypertrophy) is a rare condition in which one side of the body or a part of one side of the body (such as a hand or leg) grows significantly more than the other due to an over-production of bone or soft tissue. This overgrowth causes visible unevenness or asymmetry.
Hemihyperplasia can also impact a child’s skin, muscle, fat, and bone cells, creating noticeable growth in the face, jaw, teeth, or other areas.