A coma is defined as a prolonged state of unconsciousness. When a person is in coma, they are unaware of their environment. Even though the person is alive and appears to be sleeping, their state is different from a sleeping person. The brain is functioning at its lowest stage of alertness. The person’s organs maybe linked to machines that might be helping them to live, for example a pace maker. It we consider consciousness as a characteristic of living beings then a person in coma might not be considered living. However, a lot many metabolic activities still take place and people often come out of their comatose state, so they are living.