It is defined in the broad sense as the direct intentional killing of a person as part of the medical care being offered. Active euthanasia is defined as the killing is achieved by a direct act to kill such as lethal injection. Passive euthanasia is defined as the killing is achieved by omission of treatment and in Hong Kong they prefer the term “Forgoing life-sustaining treatment (FLST)” instead of passive euthanasia. FLST is defined as withholding or withdrawing all treatments that have the potential to postpone the patient’s death and it is only appropriate when it is the wish of a mentally competent and properly informed patient or when the treatment is considered futile. The futility is determined by balancing the burdens and benefits of the treatment towards the patient and asking whether the treatment is in the best interests of the patient. The ethical principles of “nonmaleficence” (do no harm) and “beneficence” (do good) are involved. Voluntary euthanasia is the killing at the voluntary request of the patient. Non-voluntary euthanasia is when the patient killed is either not capable of making the request or has not done so. Involuntary euthanasia is defined as the killing is against the wishes of the patient and it is treated as murder. The medical and legal fields in Hong Kong limited the discussion of euthanasia to “voluntary active euthanasia”.