Adenomyosis, also known as internal endometriosis, is a uterine condition in which there is tissue from the inner layer of the uterus (endometrium) in the muscular layer of the uterus (myometrium). The causes of this affectation are not clearly known, although it is known that it is dependent on estrogen and, among the factors that predispose to its development, we find having had at least one pregnancy and previous uterine surgeries (caesarean sections, curettage, hysteroscopies, etc).
It is also closely related to age, especially after 40 years. Therefore, in some cases it is colloquially called uterine aging.
Certain adenomyosis can only be detected by special techniques such as a 4D ultrasound or an MRI. For mild cases, there are very few treatments with manifest effectiveness and it is not fully proven that it has a negative effect on the pregnancy rates of patients. However, severe cases such as T-uterus require corrective surgery using hysteroscopy.