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)
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.

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 difficult. Gas embolism may also arise as a complication. Since the success of the procedure is totally depending on the quality of the high-resolution video images in front of surgeon's eyes, CO2 gas is not commonly used as the distention medium.
Electrolytic solutions include normal saline and lactated Ringer’s solution. Current recommendation is to use the electrolytic fluids in diagnostic cases, and in operative cases in which mechanical, laser, or bipolar energy is used. Since they are conducting electricity, these fluids should not be used with monopolar electrosurgical devices. Non-electrolytic fluids eliminate problems with electrical conductivity, but can increase the risk of hyponatremia. These solutions include glucose, glycine, dextran (Hyskon), mannitol, sorbitol and a mannitol/sorbital mixture (Purisol). Water was once used routinely, however, problems with water intoxication and hemolysis discontinued its use by 1990. Each of these distention fluids is associated with unique physiological changes that should be considered when selecting a distention fluid. Glucose is contraindicated in patients with glucose intolerance. Sorbitol metabolizes to fructose in the liver and is contraindicated if a patient has fructose malabsorption. High-viscous Dextran also has potential complications which can be physiological and mechanical. It may crystallize on instruments and obstruct the valves and channels. Coagulation abnormalities and adult respiratory distress syndrome (ARDS) have been reported. Glycine metabolizes into ammonia and can cross the blood brain barrier, causing agitation, vomiting and coma. Mannitol 5% should be used instead of glycine or sorbitol when using monopolar electrosurgical devices. Mannitol 5% has a diuretic effect and can also cause hypotension and circulatory collapse. The mannitol/sorbitol mixture (Purisol) should be avoided in patients with fructose malabsorption.

Hysteroscopy has been done in the hospital, surgical centers and the office. It is best done when the endometrium is relatively thin, that is after a menstruation. Diagnostic can easily be done in an office or clinic setting. Local anesthesia can be used. Simple operative hysteroscopy can also be done in an office or clinic setting. Hysteroscopic intervention can also be done under general endotracheal anesthesia or Monitored Anesthesia Care (MAC), but a short diagnostic procedure can be performed with just a paracervical block using the Lidocaine injection in the upper part of the cervix. The patient is in a lithotomy position.
After cervical dilation, the hysteroscope with its sheath is guided into the uterine cavity, the cavity insufflated, and an inspection is performed. If abnormalities are found, an operative hysteroscope with a channel to allow specialized instruments to enter the cavity is used to perform the surgery. Typical procedures include endometrial ablation, submucosal fibroid resection, and endometrial polypectomy. Hysteroscopy has also been used to apply the Nd:YAG laser treatment to the inside of the uterus. When fluids are used to distend the cavity, care should be taken to record its use (inflow and outflow) to prevent fluid overload and intoxication of the patient.