Alvarado Score (Appendicitis)

Risk-stratifies patients with suspected acute appendicitis using the Alvarado (MANTRELS) scoring system. Assists in clinical decision-making regarding imaging, observation, and surgical consultation.

Emergency Emergency MedicineEvidence-BasedUpdated 2026-08

Clinical Notes

Formula

Score = Migration (1) + Anorexia (1) + Nausea/Vomiting (1) + RLQ Tenderness (2) + Rebound Pain (1) + Fever (1) + Leukocytosis (2) + Left Shift (1)

Normal Range

0–10

Clinical Notes

The Alvarado score (also known as MANTRELS) was described by Alvarado in 1986 and has been extensively validated. It uses 8 clinical and laboratory parameters to estimate the probability of acute appendicitis. The maximum score is 10. Scores ≥7 are considered high probability and warrant strong consideration for surgical intervention. Scores 5–6 are equivocal and typically require further imaging or observation.

References

Alvarado A. Ann Emerg Med. 1986;15(5):557-564.
Ohmann C, et al. Dig Surg. 1999;16(6):449-457.
Tehrani HY, et al. Am J Emerg Med. 2009;27(3):347-350.

Calculator Information

Specialty

Emergency Medicine

📋 Reference Ranges

Normal Range

0–10

Reference ranges for this calculator
Classification	Range
Low probability	1–4
Moderate probability	5–6
High probability	7–8
Very high probability	9–10

What This Calculator Measures

Risk-stratifies patients with suspected acute appendicitis using the Alvarado (MANTRELS) scoring system to assist clinical decision-making regarding imaging, observation, and surgical consultation.

How to Use

Assess each of the 8 MANTRELS criteria and assign 1 point each for Migration, Anorexia, Nausea/Vomiting, Rebound, Fever, Left Shift, 2 points for RLQ Tenderness, and 2 points for Leukocytosis.
Sum all points for a total score out of 10.
Score ≤4: low probability — consider alternative diagnoses.
Score 5–6: moderate probability — clinical observation, serial examination, and imaging recommended.
Score 7–8: high probability — strong consideration for surgical consultation and CT or ultrasound imaging.
Score 9–10: very high probability — urgent surgical consultation warranted.

Interpretation Guide

A score of 7 or higher strongly suggests appendicitis and warrants strong consideration for surgical intervention. A score of 5–6 is equivocal and typically requires further imaging or observation. A score below 5 has low probability but does not exclude appendicitis.

Clinical Significance

The Alvarado score (MANTRELS) was described by Alvarado in 1986 and has been extensively validated for acute appendicitis screening. It uses 8 clinical and laboratory parameters. CT imaging remains the gold standard for appendicitis confirmation in adults.

When to Use

Adult patients presenting with acute abdominal pain suspicious for appendicitis
Initial clinical screening before imaging
Resource-limited settings where CT imaging is not immediately available

When Not to Use

As a sole basis for operative decision-making
In pregnant women, elderly patients, or young children where the score has lower sensitivity
When CT imaging is readily available and clinical suspicion is moderate to high

Limitations

Lower sensitivity in elderly patients, pregnant women, and young children.
Does not replace clinical judgment or imaging studies.
A negative score does not definitively exclude appendicitis.

Worked Example

A 25-year-old male presents with migrating abdominal pain, anorexia, nausea, RLQ tenderness, and fever.

Inputs:

migration: 1

anorexia: 1

nausea: 1

rlq-tenderness: 2

rebound: 0

fever: 1

leukocytosis: 0

left-shift: 0

Score = 1 + 1 + 1 + 2 + 0 + 1 + 0 + 0 = 6 — moderate probability; clinical observation and imaging recommended.

Evidence

Source: Emergency Medicine
Reference: Alvarado A. Ann Emerg Med. 1986;15(5):557-564.
Reviewed By: MedCalcHub Clinical Team
Version: 1.0
Updated: 2026-08

Alvarado A. Ann Emerg Med. 1986;15(5):557-564.
Ohmann C, et al. Dig Surg. 1999;16(6):449-457.

References

Alvarado A. A practical score for the early diagnosis of acute appendicitis. Ann Emerg Med. 1986;15(5):557-564. (Diagnostic study)
Ohmann C, et al. Systematic review of scores for diagnosing acute appendicitis. Dig Surg. 1999;16(6):449-457. (Systematic review)

Frequently Asked Questions

What is the Alvarado score?

The Alvarado score (MANTRELS) is a clinical scoring system that estimates the probability of acute appendicitis based on 8 clinical and laboratory parameters: Migration of pain, Anorexia, Nausea/vomiting, Tenderness in the right lower quadrant, Rebound pain, Fever, Leukocytosis, and left Shift (neutrophilia).

What does a score of 7 or higher mean?

A score of 7–8 is considered high probability for appendicitis and strongly supports surgical consultation and consideration for appendectomy. A score of 9–10 is very high probability.

Can appendicitis be present with a low score?

Yes. The Alvarado score has a sensitivity of approximately 75–95% depending on the study. A low score does not definitively exclude appendicitis, particularly in atypical populations (elderly, pregnant women, young children).

How does the Alvarado score compare to CT imaging?

CT imaging has higher sensitivity and specificity than the Alvarado score for appendicitis. The Alvarado score is a clinical screening tool that helps determine which patients should proceed to imaging. CT is the gold standard for definitive diagnosis.

Is the Alvarado score reliable in children?

The Alvarado score has been validated in pediatric populations but may be less reliable in very young children. The Pediatric Appendicitis Score (PAS) is an alternative specifically designed for children.

Disclaimer: This calculator is intended for educational and clinical decision support. The Alvarado score is a screening tool and should not replace clinical judgment, imaging studies, or specialist consultation.