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 surgical specialist is a physician who has additional training in a specific area of surgery.The American Board of Medical Specialties acknowledges the following surgical specialties: general surgery, thoracic and cardiac surgery, colon and rectal surgery, obstetrics and gynecological surgery, neurological surgery, ophthalmic surgery, oral and maxillofacial surgery, orthopedic surgery, otolaryngological surgery, pediatric surgery, plastic surgery, urological surgery, and vascular surgery.Some procedures are performed by more than one type of specialist. Also, some surgeons may choose to specialize in specific procedures within their specialty area. For example, a plastic and maxillofacial surgeon may specialize in performing rhinoplasty procedures.

An internist is a physician who focuses on the diagnosis and treatment of conditions that affect the adult population—both acute and chronic.These doctors are often who adults see as their primary physicians because they treat a broad range of illnesses that do not require surgical or specialist interventions. They also work to help a patient maintain optimal health in order to prevent the onset of disease.In addition to treating the common cold and flu, internists also treat chronic diseases like diabetes and heart disease.

A pediatric specialist is a physician who has extensive training in the diagnosis and treatment of specific conditions in children. These doctors are specialists in one particular therapy area, such as dermatology, pulmonology, surgery, or ophthalmology, in addition to being pediatricians. Pediatric specialists are who parents would take their children to when they are diagnosed with a condition requiring specialist treatment not provided by their pediatrician or primary care provider. While specialists in any area are qualified to treat children as well as adults, pediatric specialists have specific training in the way diseases affect children who are still growing and have different emotional needs than adults.

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.