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ASA Physical Status Classification: ASA Class I to VI
The ASA physical status classification sorts a patient's pre-anesthesia health into six classes: ASA I (normal healthy patient), II (mild systemic disease), III (severe systemic disease), IV (severe systemic disease that is a constant threat to life), V (moribund) and VI (declared brain-dead organ donor). An “E” is added for emergency surgery. Tick conditions below to see the class that the ASA examples point to.
Prepared by Prospyr · Reviewed October 3, 2026 · Free, no sign-up, runs in your browser
Tick the conditions that apply
The class shown is the highest ASA class among the ticked examples. Leave everything unticked for a healthy, non-smoking patient with no or minimal alcohol use.
ASA physical status
ASA I
A normal healthy patient
No conditions ticked, so this shows the healthy baseline: healthy, non-smoking, no or minimal alcohol use.
Decision support only; it does not replace clinical judgment. ASA says the final class is assigned by the anesthesiologist on the day of anesthesia care.
ASA physical status classification: the six classes and their examples
This is the ASA-approved table from the Statement on ASA Physical Status Classification System, last updated December 13, 2020. ASA describes the examples as guidelines for the clinician, and says departments may add institution-specific examples. The lists are “including, but not limited to”, so they are not exhaustive.
| Class | Definition | Adult examples |
|---|---|---|
| ASA I | A normal healthy patient | Healthy, non-smoking, no or minimal alcohol use |
| ASA II | A patient with mild systemic disease Mild diseases only without substantive functional limitations. | Current smoker; Social alcohol drinker; Pregnancy; Obesity (30<BMI<40); Well-controlled DM/HTN; Mild lung disease |
| ASA III | A patient with severe systemic disease Substantive functional limitations; one or more moderate to severe diseases. | Poorly controlled DM or HTN; COPD; Morbid obesity (BMI ≥40); Active hepatitis; Alcohol dependence or abuse; Implanted pacemaker; Moderate reduction of ejection fraction; ESRD undergoing regularly scheduled dialysis; History (>3 months) of MI, CVA, TIA, or CAD/stents |
| ASA IV | A patient with severe systemic disease that is a constant threat to life | Recent (<3 months) MI, CVA, TIA or CAD/stents; Ongoing cardiac ischemia or severe valve dysfunction; Severe reduction of ejection fraction; Shock; Sepsis; DIC; ARD or ESRD not undergoing regularly scheduled dialysis |
| ASA V | A moribund patient who is not expected to survive without the operation | Ruptured abdominal/thoracic aneurysm; Massive trauma; Intracranial bleed with mass effect; Ischemic bowel in the face of significant cardiac pathology or multiple organ/system dysfunction |
| ASA VI | A declared brain-dead patient whose organs are being removed for donor purposes | – |
Pediatric and obstetric examples from the same ASA table:
| Class | Pediatric examples | Obstetric examples |
|---|---|---|
| ASA I | Healthy (no acute or chronic disease), normal BMI percentile for age | – |
| ASA II | Asymptomatic congenital cardiac disease; Well controlled dysrhythmias; Asthma without exacerbation; Well controlled epilepsy; Non-insulin dependent diabetes mellitus; Abnormal BMI percentile for age; Mild/moderate OSA; Oncologic state in remission; Autism with mild limitations | Normal pregnancy*; Well controlled gestational HTN; Controlled preeclampsia without severe features; Diet-controlled gestational DM |
| ASA III | Uncorrected stable congenital cardiac abnormality; Asthma with exacerbation; Poorly controlled epilepsy; Insulin dependent diabetes mellitus; Morbid obesity; Malnutrition; Severe OSA; Oncologic state; Renal failure; Muscular dystrophy; Cystic fibrosis; History of organ transplantation; Brain/spinal cord malformation; Symptomatic hydrocephalus; Premature infant PCA <60 weeks; Autism with severe limitations; Metabolic disease; Difficult airway; Long term parenteral nutrition; Full term infants <6 weeks of age | Preeclampsia with severe features; Gestational DM with complications or high insulin requirements; A thrombophilic disease requiring anticoagulation |
| ASA IV | Symptomatic congenital cardiac abnormality; Congestive heart failure; Active sequelae of prematurity; Acute hypoxic-ischemic encephalopathy; Shock; Sepsis; Disseminated intravascular coagulation; Automatic implantable cardioverter-defibrillator; Ventilator dependence; Endocrinopathy; Severe trauma; Severe respiratory distress; Advanced oncologic state | Preeclampsia with severe features complicated by HELLP or other adverse event; Peripartum cardiomyopathy with EF <40; Uncorrected/decompensated heart disease, acquired or congenital |
| ASA V | Massive trauma; Intracranial hemorrhage with mass effect; Patient requiring ECMO; Respiratory failure or arrest; Malignant hypertension; Decompensated congestive heart failure; Hepatic encephalopathy; Ischemic bowel or multiple organ/system dysfunction | Uterine rupture |
* Although pregnancy is not a disease, the parturient’s physiologic state is significantly altered from when the woman is not pregnant, hence the assignment of ASA 2 for a woman with uncomplicated pregnancy.
** The addition of “E” denotes Emergency surgery: (An emergency is defined as existing when delay in treatment of the patient would lead to a significant increase in the threat to life or body part).
How to use this ASA class classifier
- Pick the example list (adult, pediatric or obstetric). Ticks in other lists still count.
- Tick every condition that applies. The result is the highest class among the ticked examples, and the conditions that set it are listed under the result.
- Add the emergency modifier if delay in treatment would significantly increase the threat to life or body part.
Your choices are saved in the page address, so you can send a result to a colleague. Nothing is stored on a server. The tool matches conditions to ASA's published examples; it does not judge severity for you. “Well-controlled” versus “poorly controlled” diabetes or hypertension, for example, is your call.
Worked examples
| Patient | Ticked examples | Result |
|---|---|---|
| Healthy, non-smoking adult, no or minimal alcohol | None | ASA I |
| Adult, current smoker, BMI 32, well-controlled hypertension | Current smoker; obesity (30<BMI<40); well-controlled DM/HTN | ASA II |
| Same patient, but diabetes is poorly controlled | Adds poorly controlled DM or HTN | ASA III (highest ticked class) |
| Adult with an MI two months ago | Recent (<3 months) MI, CVA, TIA or CAD/stents | ASA IV |
| ASA II patient needing emergency surgery | Current smoker, plus emergency | ASA II-E |
The same history after the three-month mark moves the MI example from IV to III (“history (>3 months) of MI”), which is why the time since the event matters.
ASA class in plastic surgery and procedural practices
Practices that run an operating or procedure room record a physical status class in the preoperative assessment, usually by the anesthesia provider. Keeping it in the same chart as the history, consent and anesthesia record avoids a second system. Prospyr's charting keeps those notes with the patient, and the plastic surgery practice software page shows how surgical scheduling and charting fit together.
If you also screen for other perioperative factors, the STOP-Bang calculator, the Apfel score calculator and the Caprini score calculator use published scoring in the same way.
What the ASA class does not tell you
ASA states that the classification alone does not predict perioperative risks. Used with other factors, such as type of surgery, frailty and level of deconditioning, it can help in predicting them. It is also a clinician-assigned label, so two clinicians can land on different classes. A 2017 study in Anesthesiology(Hurwitz et al., listed in ASA's own references) found that adding examples to the system improved correct assignments, which is why ASA publishes the examples table.
Frequently asked questions
What is an ASA class?
An ASA class is the American Society of Anesthesiologists physical status number, I to VI, that summarizes a patient's pre-anesthesia medical comorbidities. ASA says the system is meant to assess and communicate those comorbidities, and that by itself it does not predict perioperative risk.
Is there an ASA score calculator?
ASA physical status is a classification, not a points score, so there is nothing to add up. This tool works the way ASA's own examples table does: you tick the conditions that apply and it returns the highest class among them. A provider still decides the class.
Who assigns the ASA physical status?
ASA states that assigning a class is a clinical decision based on multiple factors. It may first be set at various points in the preoperative assessment, but the final assignment is made on the day of anesthesia care by the anesthesiologist after evaluating the patient.
What does the E in ASA 2E or ASA III-E mean?
The E denotes emergency surgery. ASA defines an emergency as existing when delay in treatment of the patient would lead to a significant increase in the threat to life or body part. It is added to the number, for example ASA II-E.
Is a smoker or someone with BMI 35 ASA I?
No. In the ASA examples, a current smoker, a social alcohol drinker, pregnancy and obesity (30<BMI<40) are listed under ASA II. Morbid obesity (BMI of 40 or more) is listed under ASA III. ASA I is a healthy, non-smoking patient with no or minimal alcohol use.
Why is pregnancy ASA II?
ASA notes that pregnancy is not a disease, but the physiologic state of the pregnant patient is significantly altered from when she is not pregnant. That is the reason ASA lists a normal pregnancy as ASA II.
Does a higher ASA class mean surgery cannot go ahead?
No. The ASA class describes comorbidity. It is not a clearance decision and it is not a rule about who may have a procedure. Those decisions belong to the anesthesiologist, the surgeon and the facility policy.
Sources and scope
- American Society of Anesthesiologists. Statement on ASA Physical Status Classification System (last amended December 13, 2020)
Definitions, ASA-approved adult, pediatric and obstetric examples, the pregnancy and emergency footnotes, and the statements on purpose and final assignment. The page now redirects to ASA's journal-hosted version; the wording used here comes from the ASA page as archived by the Internet Archive.
- Hurwitz EE, Simon M, Vinta SR, et al. Adding examples to the ASA-Physical Status classification improves correct assignments to patients. Anesthesiology 2017;126:614-22
Listed in ASA's reference list for the statement.
Decision support only; it does not replace clinical judgment. This tool matches ticked conditions to ASA's published examples. The class is assigned by the anesthesiologist, and nothing here is a clearance, a risk prediction or a treatment recommendation.