Calculate the Alvarado (MANTRELS) score to assess appendicitis probability. Evaluates symptoms, signs, and lab values to stratify low, intermediate, and high risk.
The Alvarado Score Calculator, also known as the MANTRELS score, estimates the likelihood of acute appendicitis from symptoms, exam findings, and basic laboratory results. It remains a common bedside tool for evaluating right lower quadrant abdominal pain.
The score uses eight criteria: migration of pain, anorexia, nausea or vomiting, right lower quadrant tenderness, rebound pain, elevated temperature, leukocytosis, and left shift. Right lower quadrant tenderness and leukocytosis are weighted more heavily than the other items.
The Alvarado score helps standardize the initial assessment of possible appendicitis. It can support decisions about observation, imaging, and surgical review.
It is most useful as part of the full clinical picture rather than as a stand-alone diagnosis.
Alvarado (MANTRELS) Score: • Migration of pain to RLQ = 1 point • Anorexia = 1 point • Nausea/Vomiting = 1 point • Tenderness in RLQ = 2 points • Rebound pain = 1 point • Elevated temperature ≥37.3°C = 1 point • Leukocytosis >10,000 = 2 points • Left shift >75% neutrophils = 1 point Total: 0-10 points
Result: 10 / 10 — High Risk (78-82% likelihood)
A patient with all criteria positive scores 10/10, placing them firmly in the high-risk category. Surgical consultation for likely appendectomy is strongly recommended.
Dr. Alfredo Alvarado developed this scoring system at the Regional Medical Center of Orlando in 1986 after analyzing 305 patients who presented with RLQ abdominal pain. By weighting clinical features based on their diagnostic importance, he created a practical bedside tool that could stratify patients before the widespread availability of CT scanning.
While CT scanning has become the dominant diagnostic tool for appendicitis in many settings, the Alvarado score remains valuable for initial risk stratification, determination of imaging urgency, resource-limited settings, and reducing unnecessary imaging in low-risk patients. It also serves as an important teaching tool for clinical reasoning.
Several alternative and complementary scoring systems exist, including the Appendicitis Inflammatory Response (AIR) score, the Adult Appendicitis Score, and the RIPASA score developed for Asian populations. Each has different sensitivities and specificities depending on the population studied.
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This calculator applies the original Alvarado / MANTRELS appendicitis score by summing the published weighted symptoms, examination findings, and laboratory features into the standard 0-10 total. It uses the usual low-, intermediate-, and high-probability framing so the score can support observation, imaging, or surgical review decisions in the context of suspected appendicitis.
The score is used here as a structured bedside aid rather than a stand-alone diagnosis. It does not replace serial abdominal examinations, imaging, gynecologic differential diagnosis, or pediatric- and pregnancy-specific appendicitis pathways.
A higher score suggests a greater likelihood of appendicitis and usually prompts surgical review, but imaging and clinical judgment are still important.
It is mainly a screening tool. Accuracy varies by setting, so imaging or follow-up assessment may still be needed.
It can be used in children, although pediatric-specific scores may be more appropriate in some settings.
No. A low score makes appendicitis less likely, but ongoing symptoms still need clinical reassessment.
Interpretation can be more difficult because gynecologic conditions may overlap with appendicitis symptoms.
The modified version removes the left shift criterion and uses a 9-point scale.