How does someone come out of a coma?

Coma: People emerge from coma in varied fashions and to different extents. For example, people who are in medically-induced comas may emerge from this as medication is allowed to wear off. Alternatively, a person in a coma from a disease state may emerge from coma as the disease state improves. This can be rapid (hours to days) or slow (weeks or months). Some people fully recover. Others may not.