What Is an Anesthesiologist?

The practice of anesthesia continues to evolve

An anesthesiologist is a board-certified physician who has attained either a doctor of medicine (MD) or doctor osteopathic medicine (DO) degree and chosen to specialize in the field of anesthesiology. These professionals are trained to safely administer anesthetics to induce a temporary loss of sensation or consciousness for the performance of a medical procedure. This involves a variety of drugs ranging from local numbing agents to general anesthesia.

Anesthesiologist adjusting anesthesia machine
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Anesthesiologists are an integral part of the surgical team, which includes surgeons, surgical assistants, nurses, and surgical technologists.

According to the Bureau of Labor Statistics (BLS), 30,590 anesthesiologists were practicing in the United States in 2017. The vast majority maintain private or group practices or are employed by general or surgical hospitals.


The core function of anesthesiology is the practice of anesthesia. This involves the use of topical, injected, or inhaled medications to produce a loss of sensation. Without anesthesia, many surgical and non-surgical procedures would be intolerable or unfeasible.

To administer anesthesia safely, the anesthesiologist must have expert knowledge of physiology, pharmacology, and the techniques used to support vital organ functions during an anesthetic procedure. These include:

  • The management of airways and respiration
  • The use of hemodynamic monitors to measure blood pressure
  • The various methods of cardiovascular (heart) and pulmonary (lung) resuscitation should these organ systems suddenly fail

Anesthesiologists are also expected to have a broad general knowledge of all areas of medicine and surgery.

In the United States, anesthesia care can be provided either by the anesthesiologist or a non-physician anesthesia practitioner, usually referred to as a certified registered nurse anesthetist (CRNA).

Procedural Expertise

From a procedural viewpoint, an anesthesiologist's work starts well in advance of surgery. In recent decades, the role of the anesthesiologist has expanded beyond the administration of anesthesia to include an extensive assessment of a person's ability to tolerate anesthesia. By doing so, anesthesia can be delivered safely and recovery can be smoother and problem-free.

Known as perioperative medicine, the approach involves the preoperative (before the operation), intraoperative (during the operation), and postoperative (after the operation) phases.


Prior to an operation, an anesthesiologist will conduct an assessment to better evaluate your fitness for anesthesia. Also known as the workup, the assessment typically involves:

  • A review of your current medical history
  • A review of your past medical history (especially conditions involving the heart, lungs, liver, or kidneys)
  • A review of past surgery (including adverse reactions to anesthesia)
  • Allergies (both drug and non-drug related)
  • Current medication use (paying close attention to diabetic medications, steroids, and drugs that may promote bleeding, such as aspirin and blood thinners)
  • Tobacco, alcohol, and illicit drug use

The anesthesiologist will also review your medical file for relevant lab results, particularly blood panels, electrocardiogram (EKG) readings, chest X-rays, and stress test results.

Equally important is the need to discuss any fears or questions you may have about anesthesia to select the most appropriate form for the procedure and you as an individual. It is the responsibility of the anesthesiologist to inform you about the possible risks and consequences of anesthesia.


Depending on the type of anesthesia used, you will be prepped for your procedure by the anesthesiologist, nurse, or surgical technologist. This may involve inserting an intravenous (IV) line into a vein or hooking you up to electrodes to monitor your heart and respiration.

The type of anesthesia chosen will depend largely on the surgery and your medical condition. It may include sedatives, which make you sleepy, and analgesics, which ease pain. The different types of anesthesia are broadly described as:

  • Local anesthesia (agents, either topical or injectable, given to temporarily block pain in a specific part of the body)
  • Regional anesthesia (injected agents, either spinal or epidural, to numb a portion of the body)
  • General anesthesia (an agent, given either by mask or an IV line, to induce unconsciousness)
  • Monitored anesthesia care (also known as "twilight sleep")

Depending on the condition being treated, an endotracheal tube may be inserted into your trachea (windpipe) to provide oxygen via mechanical ventilation.

Throughout the operation, the anesthesiologist will monitor your vital signs (including heart rate, blood pressure, heart rhythm, body temperature, and breathing) to ensure that you are safe and your organs are functioning normally.


Once the operation is complete, the anesthesiologist will cease the anesthetic, and you will monitored. Once you are aroused, you will be watched for side effects and complications and treated as needed.

Depending on the type of anesthetic used and/or the duration of its delivery, the anesthesiologist may conduct a separate postoperative assessment, checking for complications such as nausea, sore throat, dental injury, nerve injury, eye injury, altered lung function, or change in your mental status.


There are a number of subspecialties an anesthesiologist may decide to pursue, most of which require additional training and advanced skills assessments. These can lead to the awarding of specialist qualifications upon the completion of training.

Anesthesiologist subspecialties include:

  • Cardiothoracic anesthesia
  • Critical care anesthesia
  • Neurosurgical anesthesia
  • Obstetric anesthesia
  • Regional anesthesia (utilized in orthopedic surgeries)
  • Pediatric anesthesia
  • Hospice and palliative anesthesia

Based on their expertise in regional anesthesia and nerve blocks, many anesthesiologists will pursue a career in pain medicine. This is typically an office-based practice focused on the treatment of chronic pain, including back pain, neck pain, migraines, headaches, and nerve pain, among others. As such, you may see them in these capacities as well.

Dental anesthesia is not a subspecialty of anesthesiology but rather of dentistry, with training and certification offered by the American Dental Board of Anesthesiology (ADBA).

Training and Certification

Because anesthesiologists are medical doctors, they must complete all of the education and training required of any physician. This typically involves four years of college to attain an undergraduate degree, four years of graduate school to attain an MD or DO degree, and four years of a postgraduate residency in a certified hospital-based program.

During residency, the anesthesiologist candidate will learn a variety of skills, including chronic and acute pain management, postoperative pain control, and intensive care pain management. Upon completion, many anesthesiologists will go on to complete a year-long fellowship in a subspecialty of personal interest.

Anesthesiologists in the United States have three levels of credentialing:

  • Upon graduation from medical school, the anesthesiologist candidate must first pass the U.S. Medical and Licensing Examination (USMLE).
  • Individual subspecialties require further certification at the end of residency, obtained by the successful completion of a written and oral exam from the American Board of Anesthesiology (ABA).
  • Fellows can achieve an additional ABA-board certification in the anesthesiology subspecialties of critical care, pain medicine, and hospice and palliative medicine.

Additionally, if an anesthesiologist gets their medical degree from a school outside of the United States, they need to pass the Educational Commission For Foreign Medical Graduates (ECFMG) exam. This includes a medical proficiency exam, verification of your medical degree, and, in some cases, a language test.

Licensing of anesthesiologists is required in all states. Requirements can vary, so contact your state licensing board for anesthesiologists for further details.

Appointment Tips

Most people will only meet their anesthesiologist on the same day they are scheduled to have surgery. More often than not, the anesthesiologist will be chosen by your surgeon or the surgical chief of staff at the hospital. This doesn't mean that you cannot ask who your assigned anesthesiologist is or verify credentials on the ABA certification webpage.

If you have serious concerns about anesthesia, you can request a consultation in advance of your operation. This allows you time to ask questions important to you, some of which may include:

  • Will you or someone else be giving me anesthesia?
  • Are there different options for anesthesia for my procedure?
  • What are the chances of side effects or complications?
  • Do I have medical conditions that place me at risk?
  • Are there medications I need to stop before the operation?
  • What are the eating restrictions before my procedure?

Be sure to bring the list of drugs, supplements, herbal remedies, and other medications you may be taking.

It is equally important to find out if the anesthesiologist in on the in-network provider list of your health insurance policy. If not, you may find yourself having to pay some or all of the costs out of pocket.

1 Source
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American Society of Anesthesiologists, "Role of a Physician Anesthesiologist: When Seconds Count | Anesthesia, Pain Management & Surgery"

Additional Reading

By Andrea Clement Santiago
Andrea Clement Santiago is a medical staffing expert and communications executive. She's a writer with a background in healthcare recruiting.