"Passive euthanasia" is usually defined as withdrawing medical treatment with the deliberate intention of causing the patient''s death. For example, if a patient requires kidney dialysis to survive, the doctors disconnect the dialysis machine, allowing the patient to die soon.
This form of euthanasia is different from "active" euthanasia, or simply euthansia, where the death is caused by the use of lethal substances. It is widely considered to be criminal homicide, but voluntary passive euthanasia is considered non-criminal in several countries.
Euthanasia conducted with the consent of the patient is termed "voluntary euthanasia", which is legal in Belgium, Luxembourg, the Netherlands, Switzerland, and the US states of Oregon and Washington.
When the patient brings about his or her own death with the assistance of a physician, the term "assisted suicide" is often used.
If euthanasia is carried out on a patient, who is not in a condition to express his or her desire to die, it is called non-voluntary euthanasia.
Examples include child euthanasia, which is illegal worldwide but decriminalised under certain specific circumstances in the Netherlands under the Groningen Protocol.
It's also legal in Albania if three or more family members consent to the decision. Although both forms of euthanasia are illegal in Switzerland, assisted suicide is penalised only if it is carried out "from selfish motives".
In 1995, Australia's Northern Territory had approved a euthanasia bill. It went into effect in 1996, but Australian Parliament overturned the bill the next year.
In Colombia, the Supreme Court ruled in favour of mercy killing in 1997 and recommended removing penalties over it. But, the ruling has not gone into effect as the Colombian Congress is yet to approve guidelines for it.
It is illegal for anyone to actively contribute to someone's death in Ireland. However, it is not illegal to remove life support and other treatment if a person requests for it -- in other words, passive euthanasia is legal.