The individual patient may be persuaded to end his or her life in order to ease the financial burden on relatives or the state. Once society approves of euthanasia, it will not be long before individuals suffering from physical or mental illness, not in a position to make a choice, will have the choice made for them.
I qualified as a doctor 16 years ago and I have not yet come across a case of "active" euthanasia in hospital. I have, however, met elderly patients worried about being "put to sleep" by the doctor. If the euthanasia lobby ever get their way then it will be the doctors who will be expected to carry out their will. Surely, one doesn't need five years at medical school to learn to kill.