Critical care is provided for patients who are suffering from life-threatening conditions. The doctors who work with these people are often called intensivists. They focus on a range of different issues, so they can serve people who need immediate and life-saving care. Since people who need critical care are suffering from such a wide variety of issues, intensivists must have a thorough understanding of diverse types of medical issues and the devices and medications needed to treat them.

A hospitalist is a doctor who works only in a hospital setting. Hospitalists care for patients who are staying in the hospital to recover from an illness or a surgery. Most hospitalists are also internists, and many primary care doctors are hospitalists. Some of them also work in subspecialties or have work in other areas early in their careers. Hospitalists coordinate care for patients admitted in the hospital. They play the role of Primary care doctors in hospital settings.