What happens when a completely healthy person wants their leg amputated? Gregg is 55 and does not feel physically whole. This is despite the fact that he is physically healthy and able-bodied. Gregg believes he is incomplete with two legs and it has been his life-long struggle to get doctors to agree that removing one of his legs is the right thing for him. He isn't delusional. He knows what he is asking for and knows it is strange. But he cannot help his feelings. Gregg suffers from a rare but genuine psychological disorder - a form of body dysmorphia. And Gregg is not alone. Although Body Dysmorphia is rare, a worldwide network of sufferers is growing and demanding treatment. It affects both men and women and each person has a precise sense of which limb or limbs they want removed. Cases were cited a hundred years ago but still very little is known about the disorder. No one knows what causes it and very few psychiatrists have even encountered patients with the disorder. All that the patients seem to have in common is a strong memory of the first amputee they saw. They also report that the feelings started in childhood. However, the profession is now being forced to respond and devise methods of treatment. If not treated, it has been reported that suffers can go to extreme lengths to remove the unwanted limbs themselves. Some have even committed suicide. The difficulty with the condition is that the conventional methods for treating psychological problems, drugs and therapy, do not seem to be effective. The only treatment that does seem to be effective is surgery - actually removing the limb. The idea of using surgery is highly controversial and has divided the medical community. Some physicians consider it much too drastic a measure, possibly conflicting with their Hippocratic oath, not to cause harm. Others believe that it is the only way to free the patient of their obsession, 'curing' them of their psychological problem. At the present time, there is only one surgeon in Britain who has been prepared to perform such operations and who has publicly defended his decision. He has operated on two patients, both of who claim to be delighted with their new body-image and now free to get on with the rest of their lives. There are many other patients who seek similar treatment. Horizon 'Complete Obsession' follows a year in the lives of people who are body dysmorphic and are determined to have their limbs surgically removed. It follows the process they go through to try and achieve their goal.