Exostosis is a medical condition characterized by the abnormal growth of bone tissue on the surface of a bone. This growth can occur in various parts of the body, including the skull, spine, and limbs. Exostoses can be caused by factors such as repetitive stress, injury, or certain genetic conditions. These bone growths are usually benign, meaning they are not cancerous, but they can sometimes lead to discomfort or complications if they press against nearby tissues. Treatment options may include monitoring the growth or surgical removal if it causes pain or functional issues.