There are very many persons in this world who, at some moment or the other, are troubled by some sensation of instability, or movement or incertainty. The intensity of this sensation is no indicator for the seriousness of its cause, neither is the exactitude of its description by the patient. The examination of the equilibrium system is certainly possible but it is a time-consuming procedure. It will hardly be feasible to examine, thoroughly and completely, all those patients who come to their doctor with the story that they are or have been giddy, but the doctor should know that dysfunction of nearly any organ or organ system in the body can disturb the fine interaction of all the organs and systems which together lead to that intricate equilibrium which we call health. If anything goes wrong, the patient may translate this disequilibrium into terms of vertigo, dizziness, giddiness or loss of balance, depending upon what he feels, what he knows, and where he comes from. It is easy to understand why patients may have difficulty in explaining their feelings and why their complaints are often so vague as to be meaningful only to a specialist. As those feelings are not clear to the patient either, well-directed question will be necessary to dig up hidden information. Good knowledge of both, the morbid anatomy and physiology of the entire equilibrium system; of the various clinical pictures of disequilibrium; of the background of the methods of examination that can be used; of the information those examinations can give and what they cannot give; how one can make the correct diagnosis, what this diagnosis really means and how it can lead to an appropriate therapy, i.e. treatment of the cause of the ailment.