Dystonia is a group of movement disorders, all of which are characterized by uncontrolled and sustained muscle contraction. This can result in the twisting of body parts, repetitive movements, or unusual and uncomfortable postures. The condition has many causes, ranging from hereditary defects to trauma, infection and toxins. Some of these causes are induced by pharmaceuticals and are reversible. However, most cases are permanent and incurable, meaning treatment focusses on dealing with the symptoms and any triggers that set off the symptoms.