This usually happens when the patient is in a Persistent Vegetative State, or PVS. Individuals in a PVS have massive brain damage that are in a coma, and most likely will never regain consciousness ( No Author, http://www.religioustolerance.org).
There are many reasons people would decide on assisted suicide. First of all, there are many terminal illnesses that are very painful and cause a great deal of distress. First, there are diseases such as multiple sclerosis, muscular dystrophy, and ALS (also known as Lou Gerig's disease). These diseases have a very negative effect on the human body. These diseases attack either the body's ability to control itself, or attack the body's muscles directly. Most people who suffer from these diseases do not have a very long or comfortable life. To many, choosing when one's death will occur would be preferable to dying once the body finally failed.
There are also the more common diseases, like cancer, that usually do not lessen the person's ability to continue day-to-day activities, but are no less painful. Most of the time, the person is emotionally destroyed, as well as physically destroyed. Most people would rather decide the time of their death with this condition also.
Disease would not be the only time assisted suicide is considered. Many times, people that had a perfectly healthy, normal life are seriously injured in some sort of accident. These people may decide that life in the present form is no longer the preferred way to continue. Many people decide that life with diminished or little brain capacity or missing limbs decide that they do not want to continue their existence. .
One of euthanasia's strongest defenders is Dr. Jack Kevorkian, sometimes known as "Dr. Death". Dr. Kevorkian was born on May 28, 1928 in Pontiac, Michigan to Armenian immigrants. In 1952, he graduated from the University of Michigan medical school, specializing in pathology.