Nothing is eternal in the Universe apart from for the 'theory of transition' as told by Lord Gautama Buddha, which involuntarily demands that a human being leave the world at a certain point of time.
Euthanasia is a highly contentious subject – whether it agrees with our values and moral principles, is it a brutal and cold-blooded execution or sensible and humane.
Very often there are cases of litigation and petitions being filed before courts on behalf of the family members of a patient who is suffering for years, demanding a painless death for him or her, relieving the patient from unbearable trauma.
Most of the nations and courts reject the concept of mercy killing citing that no one is entitled to terminate the life of a patient suffering from a terminal ailment or who is on a life support system as it is extremely inhuman and murderous.
According to the people who oppose the concept of euthanasia, with the advancement in medical science, there is always an outside chance for miracles and hence it is always preferable not to give up hope. The law of nature must be allowed to take its course, and medical practitioners must not be permitted to intervene with it.