Emergency Medicine
Alvarado Score
Likelihood of acute appendicitis.
Education and reference only. Not a substitute for clinical judgement, local policy or product labelling. Always verify before clinical use. Values are calculated in your browser and never stored.
Background
The Alvarado score estimates the likelihood of acute appendicitis in a patient presenting with abdominal pain, helping to structure assessment and guide decisions on observation, imaging or surgery. It combines symptoms, signs and two laboratory findings, summarised by the mnemonic MANTRELS: Migration of pain to the right iliac fossa, Anorexia, Nausea/vomiting, Tenderness in the right iliac fossa, Rebound tenderness, Elevated temperature, Leucocytosis and Shift of the white-cell count to the left. Tenderness and leucocytosis score 2 each, the rest 1 each, for a maximum of 10.
Interpreting the result
A score of 0–4 makes appendicitis unlikely, supporting discharge with safety-netting or an alternative diagnosis. A score of 5–6 is compatible with appendicitis and usually prompts observation or imaging. A score of 7–10 makes appendicitis probable and warrants surgical review. The score supports, rather than replaces, clinical assessment, and imaging is increasingly used in the intermediate range.
Worked example
A young adult with migratory right iliac fossa pain (1), anorexia (1), nausea (1), right iliac fossa tenderness (2), rebound tenderness (1) and a temperature of 38°C (1) scores 7. This makes appendicitis probable and prompts surgical review and consideration of imaging.
Pearls / pitfalls
- It is a probability aid, not a diagnosis; a high score still warrants surgical assessment and often imaging rather than direct operation.
- Specificity is modest, so intermediate scores frequently need imaging, particularly ultrasound or CT, to clarify.
- It performs less reliably in women of reproductive age (gynaecological mimics) and in young children.
- A low score is reassuring but should be combined with safety-netting and reassessment, as appendicitis can evolve.
Evidence & validation
Developed by Alvarado from a retrospective series and validated in many subsequent studies, with generally good sensitivity but more limited specificity. It is widely used to risk-stratify suspected appendicitis, often alongside imaging, though it performs less consistently in women and children.
Frequently asked questions
What Alvarado score suggests appendicitis?
A score of 7–10 makes appendicitis probable and warrants surgical review. A score of 5–6 is intermediate and usually prompts observation or imaging, while 0–4 makes appendicitis unlikely.
Does a high score mean immediate surgery?
Not necessarily. A high score raises the probability and prompts surgical assessment, but management often includes imaging and reassessment. The decision to operate is clinical, not based on the score alone.
How accurate is the Alvarado score?
It has reasonably good sensitivity for ruling out appendicitis but more limited specificity, so positive results need confirmation. Accuracy is lower in women of reproductive age and in children.
Is it reliable in women and children?
It is less reliable in women of reproductive age, where gynaecological conditions can mimic appendicitis, and in young children. Imaging and specialist assessment are particularly important in these groups.
What does the score not cover?
It does not exclude alternative diagnoses or assess complications such as perforation. A low score should still be accompanied by safety-netting, as appendicitis can develop over time.
References
- Alvarado A. A practical score for the early diagnosis of acute appendicitis. Ann Emerg Med. 1986;15(5):557–564.
- Ohle R, O'Reilly F, O'Brien KK, et al. The Alvarado score for predicting acute appendicitis: a systematic review. BMC Med. 2011;9:139.
About the creator
Alfredo Alvarado
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