Educational Content: This article is for informational purposes only and does not constitute medical advice. Always consult a healthcare provider for diagnosis and treatment.

Definition of Adenomyosis

Medically reviewed by Min Clinic Staff | Updated: January 2026

Adenomyosis: A common, benign condition of the uterus in which the endometrium (the inner uterus) grows into the adjacent myometrium (the uterine musculature located just outside the endometrium). The myometrium may respond to this intrusion with muscular overgrowth. If an island of endometrial tissue is contained within the myometrium, it forms an adenomyoma. Also known as endometriosis interna, endometriosis uterina, adenomyosis uteri, and adenomyometritis.