People say that a nose job can change your appearance so much that you aren't recognisable. Is this true?

While the rhinoplasty procedure does  make dramatic changes in the nose, the changes  patient's are seeing are in the order of millimeters, so will  the nose changes shape slightly,  it will not make patients unrecognizable.   Digital computer imaging  would be helpful to understand what can be accomplished with your nose upon your facial features, and then you can make your decision to move forward with a rhinoplasty procedure. For many before and after rhinoplasty examples, please see link and the video below

The answer, without any hesitation is no. If someone told you this, it is a myth and no way possible. The whole purpose of a nose job is to balance the features of your nose with the features of your face. Yes, it can 'change' the look of your face, but you will still look like you. What it typically does, is rather than draw attention to your nose, shift the attention other areas of your face like your eyes. Imagine, if someone has a big bump or a large nose, its human nature to focus our attention on a part of your face that may seen 'off balance' with the rest. Once the nose is balanced with your face, our eyes will move away and focus the attention where they should, on the other persons eyes. James P. Bonaparte, MD, MSc, FRCSCHead and Neck Surgerypracticing in Facial Plastic and Reconstructive SurgeryAssistant Professor, University of OttawaOttawa, Ontario, Canada

An artistically performed rhinoplasty should not change your appearance drastically. You should end up looking like a more refined version of yourself--not someone different!