Home › Calculators › Alvarado Score
Calculator · Likelihood of acute appendicitis
Alvarado Score
Eight clinical and laboratory features (mnemonic MANTRELS), maximum 10 points. Supports — never replaces — clinical judgement and imaging. Performs less well in women of childbearing age, where gynaecological causes must be excluded.
What it asks
| Criterion | Points |
|---|---|
| Migration of pain to right iliac fossa | No — 0 Yes — 1 |
| Anorexia | No — 0 Yes — 1 |
| Nausea or vomiting | No — 0 Yes — 1 |
| Tenderness in the right iliac fossa | No — 0 Yes — 2 |
| Rebound tenderness | No — 0 Yes — 1 |
| Elevated temperature > 37.3 °C | No — 0 Yes — 1 |
| Leukocytosis — WBC > 10 × 10⁹/L | No — 0 Yes — 2 |
| Neutrophil left shift > 75% | No — 0 Yes — 1 |
How to read the score
| Score | Means | What to do |
|---|---|---|
| 0–3 | Low probability | Appendicitis less likely. Consider alternative diagnoses and a period of observation. Discharge only with clear safety-netting. Alvarado defines no band below 5 — a low score does not exclude appendicitis, and a convincing examination outranks it. |
| 4–6 | Equivocal | Imaging indicated — ultrasound first in young women and children, CT in older adults. Observe with serial examination. |
| 7–10 | High probability | Refer to the surgical team. Keep nil by mouth, IV fluids, analgesia, and βhCG in any woman of childbearing age. |
Before you use it
Always check a pregnancy test in women of childbearing age before attributing right iliac fossa pain to appendicitis.
Source: Alvarado, Ann Emerg Med 1986 / RCS guidance
Checked, and shown
Every threshold on this page was checked against its primary source by a practising doctor. Here is what that involved, and what it found.