Hysteroscopy is the inspection of the uterine cavity by endoscopy with access through the cervix. It allows for the diagnosis of intrauterine pathology and serves as a method for surgical intervention (operative hysteroscopy). Hysteroscope A hysteroscope is an endoscope that carries optical and light channels or fibers. It is introduced in a sheath that provides an inflow and outflow channel for insufflation of the uterine cavity. In addition, an operative channel may be present to introduce scissors, graspers or biopsy instruments. A hysteroscopic resectoscope is similar to a transurethral resectoscope and allows entry of an electric loop to shave off tissue, for instance to eliminate a fibroid. A contact hysteroscope is a hysteroscope that does not use distention media. Procedure Hysteroscopy has been carried out in hospitals, surgical centers and doctors' offices. It is best carried out when the endometrium is relatively thin, that is after a menstruation. Both diagnostic and simple operative hysteroscopy can be carried out in an office or clinic setting on suitably selected patients. Local anesthesia can be used. Analgesics are not always necessary. A paracervical block may be achieved using a lidocaine injection in the upper part of the cervix. Hysteroscopic intervention can also be done under general anesthesia (endotracheal or laryngeal mask) or monitored anesthesia care (MAC). Prophylactic antibiotics are not necessary. The patient is in a lithotomy position during the procedure. Cervical dilation The diameter of the modern hysteroscope is generally small enough to conveniently pass the cervix directly. For a proportion of women cervical dilation may need to be performed prior to insertion. Cervical dilation can be performed by temporarily stretching the cervix with a series of dilators of increasing diameter. Misoprostol prior to hysteroscopy for cervical dilation appears to facilitate an easier and uncomplicated procedure only in premenopausal women. Insertion and inspection The hysteroscope with its sheath is inserted transvaginally guided into the uterine cavity, the cavity insufflated, and an inspection is performed. Insufflation Media The uterine cavity is a potential cavity and needs to be distended to allow for inspection. Thus, during hysteroscopy, either fluids or CO2 gas is introduced to expand the cavity. The choice is dependent on the procedure, the patient’s condition, and the physician's preference. Fluids can be used for both diagnostic and operative procedures. However, CO2 gas does not allow the clearing of blood and endometrial debris during the procedure, which could make the imaging visualization