Anesthesiologists are physicians who are trained to administer anesthetics, which are medicines used to block nerve sensation. Anesthesia can be either local to one specific part of a body, like a tooth, or regional to block feeling to a larger portion of the body, such as during an epidural for child birth. It can also be more general to block sensation to the entire body, resulting in unconsciousness.Anesthesiologists assist in surgery by determining how much anesthesia is necessary and by monitoring the patient's level of responsiveness and vital signs throughout the procedure. The anesthesia specialist will also bring the patient out of anesthesia and then continue to monitor his or her vital signs post-operation.Besides assisting in surgeries, anesthesiologists may also treat patients suffering from chronic pain.

Also sometimes referred to as intensivists, critical care specialists are physicians with specialized training in the diagnosis and management of life-threatening conditions, such as those that affect vital organs like the heart and lungs, those that make breathing difficult or impossible, and those that affect entire organ systems, like the renal system. Critical care specialists are typically found in a hospital's intensive care unit where they monitor patients with life-threatening conditions and make determinations as to the best course of treatment.

A pain management specialist is a physician with advanced knowledge and training in diagnosing and treating pain. These doctors do not come from one particular discipline, but rather use their respective backgrounds to contribute a varied approach to the field of pain management. These specialists use their different skills and training in pain management to treat pain stemming from different causes - whether it's neuropathic pain or headache, or the result of injury, a surgical procedure, cancer or another illness. Pain management specialists are primarily trained as anesthesiologists, physiatrists, interventional radiologists, neurologists, osteopaths, or primary care physicians.