An Intensivist is a certified physician with advanced training who provides special care for critically ill patients.

Any illness which threatens life needs critical care. These include illnesses that affect the heart, lungs, and kidney such as heart attack, pneumonia, respiratory failure, kidney failure. Multiple organ failure, serious injuries such as a car crash, poisoning, burns etc.

Critical care is the ongoing care of a patient who is still in a dangerous condition or requires advanced care and is generally long-term. Emergency care on the other hand deals with injuries or conditions, minor or otherwise, that require immediate medical attention and is almost always short-term.