Endoscopy is a medical procedure which allows to visualize body structures from the inside using an endoscope, an instrument used to examine the interior of a hollow organ or cavity of the body. Unlike most other medical imaging devices, endoscopes are inserted directly into the organ. There are many different types of endoscope, and depending on the site in the body and the type of procedure, endoscopy may be performed by a doctor or a surgeon, and the patient may be fully conscious or under general anaesthetic. Endoscope can also refer to using a borescope in technical situations where direct line of-sight observation is not feasible.