When its storage capacity is exhausted, the overflow passes from the liver into the bloodstream and is carried to other places, primarily the brain and the cornea of the eye. The retention of copper begins at birth, but owing to the protective role of the liver it may take ten to thirty years before the liver is overwhelmed and symptoms of liver disease manifest themselves. These can range from the development of jaundice and ascites to acute liver failure. The British Liver Trust has a leaflet 'Your liver lets you live' which gives further information on symptoms of liver disease. Copper accumulation in the brain can present itself in two ways - as psychiatric disorders such as depression, mood swings or suicidal impulses, or as physical symptoms including slurred speech, failing voice, drooling, tremors, or difficulty in swallowing.
Muscular control can deteriorate until the patient is bedridden and helpless.
The presence of both psychiatric and physical symptoms makes Wilson's disease difficult to diagnose and especially prone to misdiagnosis. During adolescence, anxiety or depression can be misinterpreted as normal adjustment difficulties, rather than indications of a potentially fatal illness. It is possible to screen for Wilson's disease with a simple blood test measuring copper and the copper binding protein known as caeruloplasmin. However this is not always present. Although Wilson's disease is fatal if undetected, effective treatment is available even in advanced cases.