Attacks of vertigo and dizziness afflict hundreds of thousands of people every year in the UK. One in three of us under 65 years old will have experienced a balance disorder. For some, problems with their sense of balance are so severe that a trip outside the house becomes a disorientating nightmare. Many become reclusive and depressed. In this edition of Case Notes, Dr Mark Porter talks to patients, doctors and other clinical specialists about the various conditions which cause vertigo and disabling dizziness. Mark visits the one-stop Balance Clinic at Guys Hospital in London where patients are assessed and treated for a range of balance disorders. These include the most common varieties such as benign paroxsymal positional vertigo and labyrinthitis. One expression of these complaints is visual vertigo. It's also known as Supermarket Syndrome because the visual patterns of moving down the packet-lined aisles triggers attacks of disorientation. Fortunately many patients can be helped with sessions of special physiotherapy exercises rather than drugs and surgery. Mark joins a session in the clinic's gym to hear how these cheap and simple therapies work. There are also rarer, stranger balance upsets such as dehisence of the superior semicircular canal. Loud noises bring on severe attacks of vertigo. One allied symptom is that sufferers can also hear the sound of their eyeballs moving. Mark hears about the kinds of surgery possible for those patients stricken with vertigo that cannot be treated with less radical interventions. Producer: Andrew Luck-Baker.