Alvarado Score for Appendicitis
Estimates likelihood of acute appendicitis in patients with right iliac fossa pain
How to use & interpret
The Alvarado (MANTRELS) score estimates the likelihood of acute appendicitis from symptoms, signs and white cell count. As a guide: ≤4 makes appendicitis unlikely (consider discharge with safety-netting or alternative diagnosis), 5–6 is equivocal (observe/re-examine or image), and ≥7 makes it likely (surgical review).
It is most useful for ruling out appendicitis at low scores. It is less reliable in women of reproductive age and in children, and modern pathways increasingly combine it with imaging (ultrasound or CT) rather than proceeding to surgery on the score alone.
Score interpretation
Alvarado 1–4: Appendicitis unlikely
→ Observe; analgesia; repeat examination in 4–6h; consider discharge with return advice
Alvarado 5–6: Possible appendicitis
→ Admit for observation; CT abdomen/pelvis; surgical review
Alvarado 7–10: Likely appendicitis
→ Urgent surgical review; theatre preparation; IV antibiotics
Interpretation bands for the Alvarado. Apply clinical judgement and local guidance.
Frequently asked questions
Should a high Alvarado score go straight to theatre?
Not automatically. A high score raises probability and warrants urgent surgical assessment, but imaging and clinical judgement still guide the decision, particularly in women and children.
References
- Alvarado A. A practical score for the early diagnosis of acute appendicitis. Ann Emerg Med. 1986;15(5):557–64.
Related
Curated clinical cross-links plus same-class fallbacks.
- Tranexamic Acid (ICU/Trauma/Surgical) · Antifibrinolytic
- Methoxyflurane · Inhaled Analgesic — Acute Pain
- Fentanyl Transdermal Patch (Elderly Chronic Pain) · Opioid Analgesic — Transdermal Patch
- Morphine Slow-Release (Elderly Chronic Pain) · Opioid Analgesic — Modified-Release Oral
- Cefuroxime · Second-Generation Cephalosporin — Respiratory / Surgical Prophylaxis
- Ertapenem · Carbapenem — ESBL / Complicated Intra-Abdominal / Community OPAT
- Difficult Airway Algorithm (DAS) · DAS 2015; Royal College of Anaesthetists
- Major Haemorrhage Protocol · NICE NG24; UK MHP guidelines
- New-Onset Atrial Fibrillation · ESC 2020 AF Guidelines; NICE NG196
- Hypertensive Emergency · ESC/ESH 2018 Hypertension Guidelines; NICE NG136
- Bradycardia Management · Resuscitation Council UK ABCDE; ESC 2021 Pacing Guidelines
Featured in these MRCEM clinical pathways
The Alvarado is covered in detail — with RCEM/NICE evidence base, indications and pitfalls — in the following exam-focused pathways on our sister siteReviseMRCEM.
MRCEM Primary / Intermediate / OSCE candidates: each pathway includes exam-style questions, RCEM/NICE citations, and FAQ summaries.
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.