Indwara yumugongo igizwe na 2% kugeza 7% byindwara zose zifata imitsi iterwa na bagiteri, ibihumyo, kandi gake cyane na parasite. Hafi ya kimwe cya kabiri cyibibazo byanduye byumugongo biherereye mu ruti rwumugongo, birenze gato kimwe cya gatatu cyumugongo wa thoracic, naho ibindi bisigaye mu ruti rwumugongo.