Endometriosis is diagnosed through a procedure called laparoscopy.

Doctors may try a variety of methods to rule out endometriosis but the laparoscopic procedure is the only way to give a definitive diagnosis to determine the severity. Though the laparoscopy is usually a one day procedure, the patient in usually placed under general anesthesia. The doctor will make a small incision in the abdomen through which the laparoscope can be inserted to view the reproductive organs. The doctor will then be able to determine the number, size, and location of existing endometriomas.

Less often, endometriosis may be detected through a pelvic ultrasound, though this is less accurate as the endetriomas must be at least one centimeter to be detected. Hormonal drugs may also be used initially to rule out endometriosis prior to more invasive procedures.