Hysteroscopy is a very safe procedure and complications are rare. The main risks are infection and making a hole in the womb (known as a perforation). Perforations are riskiest when they occur whilst cutting energy is being used in the womb as it could then cause injury to bowel or bladder. Some hysteroscopic procedures such as fibroid resections can be associated with heavy bleeding. With prolonged hysteroscopic procedures, for instance for resecting large fibroids, large volumes of the distension fluid used during the operation may enter the blood circulation; this is called fluid overload.