About the Los Angeles Classification of Erosive Oesophagitis
Grade on mucosal breaks only, assessed in a fixed order. Involving 75% or more of the circumference is grade D; continuous between the tops of two or more folds is grade C; longer than 5 mm without bridging folds is grade B; and 5 mm or less without bridging folds is grade A. The order matters because circumferential extent outranks continuity, which outranks length. Two clinical points follow: grades C and D are generally accepted as confirming gastro-oesophageal reflux disease without further testing, while grade A is found in a proportion of asymptomatic people and confirms much less. A mucosal break requires a discrete line of demarcation — erythema, oedema or friability alone is not gradeable.
Formula
No mucosal break → not erosive oesophagitis
Otherwise assessed in this order:
≥ 75% of circumference → Grade D
Continuous between tops of ≥ 2 mucosal folds → Grade C
Longest break > 5 mm → Grade B
Otherwise (break ≤ 5 mm, not bridging folds) → Grade A- Mucosal break
- An area of slough or erythema with a discrete line of demarcation from adjacent normal mucosa. The unit the whole classification is built on.
- Continuity between folds
- A break extending between the tops of two or more mucosal folds. This is the A/B versus C/D divide.
- Circumferential extent
- 75% or more of the oesophageal circumference defines grade D.
- The order of assessment matters. Circumferential extent outranks fold continuity, which outranks break length — a 3 mm break that bridges two folds is grade C, not grade A.
- Only mucosal breaks are graded. Erythema, oedema, friability and increased vascularity are not breaks and have no grade.
- There is no grade 0. A normal oesophagus is reported as no erosive oesophagitis, not as LA grade 0.
- Grade depends on the worst finding, not on how many breaks there are. Twenty short non-bridging breaks remain grade A or B.
- Acid suppression heals erosions. An endoscopy performed on a proton pump inhibitor will under-grade, and often shows nothing at all — grade before treatment where the diagnosis matters.
- Strictures, ulcers and Barrett's segment are recorded separately. Unlike the older Savary-Miller system, the LA classification deliberately grades breaks only.
Interpreting the result
Grades C and D are objective evidence of gastro-oesophageal reflux disease, and in a patient with typical symptoms they close the diagnostic question — further reflux monitoring to establish the diagnosis is unnecessary. Both warrant a proton pump inhibitor and a follow-up endoscopy after healing, because severe erosive disease can conceal an underlying Barrett's segment that only becomes visible once the erosions resolve; grade D in particular carries the highest acid exposure and the highest rate of stricture and Barrett's. Grades A and B are weaker evidence. Grade A especially is found in a proportion of asymptomatic people, has the lowest interobserver agreement in the system, and correlates loosely with pathological acid exposure — so where the diagnosis genuinely matters, such as before antireflux surgery or when symptoms persist on therapy, reflux monitoring gives a firmer answer than a low grade does. The other thing worth checking at grades A and B is whether the finding was really a break at all.
| Score | Band | What it means | Action |
|---|---|---|---|
| No mucosal breaks | No erosive oesophagitis | Does not exclude reflux disease — most patients with troublesome reflux symptoms have non-erosive disease | Consider reflux monitoring where symptoms persist; do not record erythema alone as grade A |
| Grade A | One or more breaks ≤ 5 mm, not bridging folds | The mildest grade. Found in a proportion of asymptomatic people; weakest interobserver agreement and loosest correlation with acid exposure | Treat symptomatically; where the diagnosis matters, reflux monitoring is more informative than the grade |
| Grade B | One or more breaks > 5 mm, not bridging folds | Moderate erosive disease | Proton pump inhibitor; reassess symptomatically |
| Grade C | Break continuous between tops of ≥ 2 folds, < 75% circumference | Generally accepted as confirming gastro-oesophageal reflux disease without further testing | Proton pump inhibitor; repeat endoscopy after healing to exclude underlying Barrett's oesophagus |
| Grade D | Breaks involving ≥ 75% of the circumference | The most severe grade; highest acid exposure and highest rate of stricture and Barrett's oesophagus | Proton pump inhibitor with consideration of long-term maintenance; repeat endoscopy after healing |
What the LA Classification (Oesophagitis) needs (4 inputs)
- Presence of mucosal breaks
- A break is an area of slough or erythema with a discrete line of demarcation from adjacent normal mucosa. Erythema alone, oedema alone and friability alone do not qualify — grading those as LA A is the commonest way the classification is inflated.
- Circumferential involvement of 75% or more
- Assessed first, because it outranks every other feature and defines grade D on its own.
- Continuity between the tops of two or more mucosal folds
- The A/B versus C/D divide. It is about a break bridging the tops of adjacent folds, not about how long the break is.
- Longest break more than 5 mm
- Separates grade A from grade B, and only becomes relevant once no break bridges two folds.
What it returns
- LA grade
- A, B, C, D, or no erosive oesophagitis where no mucosal breaks are present.
- Which feature determined the grade
- Reported explicitly, since a grade D reached by circumferential involvement and a grade C reached by fold continuity are different findings that happen to be adjacent on the scale.
How it is calculated
The classification was built around a single reproducible unit — the mucosal break — after earlier systems proved unreliable precisely because they mixed different kinds of finding on one scale. Savary-Miller, the main predecessor, placed strictures and Barrett's oesophagus at the severe end alongside erosions, which meant a patient could be graded severe for a complication that had nothing to do with current inflammatory activity, and endoscopists disagreed about where the boundaries fell. The Los Angeles group restricted grading to breaks and then chose two dimensions that could be judged consistently: whether a break bridges the tops of adjacent mucosal folds, and what proportion of the circumference is involved. Fold continuity turns out to be a more reproducible judgement than absolute length, which is why it sits above length in the hierarchy — an endoscopist can see whether a break crosses from one fold top to another far more reliably than they can estimate millimetres on a curved luminal surface.
Facts & figures
| Ask | If yes | Note |
|---|---|---|
| Any mucosal break? | Continue; if no, not erosive oesophagitis | A break needs a discrete demarcation line |
| ≥ 75% of circumference? | Grade D | Outranks everything below |
| Continuous between tops of ≥ 2 folds? | Grade C | About bridging folds, not length |
| Longest break > 5 mm? | Grade B | Only relevant once no break bridges folds |
| Otherwise | Grade A | Break ≤ 5 mm, not bridging folds |
A 3 mm break that bridges two fold tops is grade C, not grade A — the hierarchy, not the size, decides.
| Grade | Confirms GORD? | Practical consequence |
|---|---|---|
| No breaks | No | Non-erosive reflux disease is the commonest phenotype; consider reflux monitoring |
| A | Weakly | Occurs in asymptomatic people; reflux monitoring more informative if the diagnosis matters |
| B | Partially | Supportive but not definitive |
| C | Yes | No further reflux testing needed to establish the diagnosis |
| D | Yes | As above, plus highest risk of stricture and Barrett's |
This asymmetry is the main clinical value of the classification: it identifies who needs a pH study and who does not.
Evidence
Validation — Lundell et al.
1999Study of the clinical and functional correlates of the Los Angeles classification, examining the relationship between endoscopic grade, symptoms and oesophageal acid exposure, and providing further validation of the system's reproducibility.
Established the classification's clinical and functional correlates, showing that grade tracks acid exposure and symptom severity, and confirming reproducibility superior to earlier systems that mixed breaks with complications.
ACG clinical guideline on GORD
2022American College of Gastroenterology clinical guideline on the diagnosis and management of gastro-oesophageal reflux disease.
Treats LA grade C and D oesophagitis as objective evidence of gastro-oesophageal reflux disease sufficient to establish the diagnosis without reflux monitoring, while noting that grade A carries much weaker diagnostic weight.
Lyon consensus 2.0
2024International consensus update on the modern diagnosis of gastro-oesophageal reflux disease, defining conclusive and borderline evidence across endoscopic and physiological testing.
Retains LA grade C and D as conclusive evidence of reflux disease, and explicitly does not accept grade A as conclusive — formalising the asymmetry between the grades.
Interobserver agreement in a clinical trial setting
2024Comparison of LA grades assigned by local investigators against central adjudicators within a clinical trial.
Found meaningful disagreement between local and central grading, concentrated at the milder grades — supporting the practice of treating grade A with caution and relying on grades C and D for diagnostic certainty.
How it compares
LA Classification (Oesophagitis) vs Savary-Miller classification
Superseded. Savary-Miller mixed mucosal breaks with strictures and Barrett's oesophagus in a single scale, which made it unreproducible.
By placing complications at the severe end alongside erosions, Savary-Miller conflated current inflammatory activity with the consequences of past disease, and endoscopists disagreed about where the boundaries fell. The Los Angeles classification grades breaks only and records complications separately, which is the change that made grading reproducible enough for clinical trials.
LA Classification (Oesophagitis) vs Prague C & M criteria
Complementary — LA grades the erosions reflux causes, Prague describes the columnar metaplasia it can produce, and both may be reported from one endoscopy.
The two describe different consequences of the same disease process and frequently coexist. The practical link is that severe erosive oesophagitis can obscure an underlying Barrett's segment, so a Prague classification recorded during active grade C or D disease may understate the extent and should be repeated after healing.
LA Classification (Oesophagitis) vs Rome IV functional heartburn
Mutually exclusive by definition — functional heartburn requires the absence of erosive oesophagitis, so any LA grade rules it out.
Rome IV functional heartburn describes retrosternal burning without objective evidence of reflux disease, eosinophilic oesophagitis or a motility disorder, and without response to acid suppression. A patient with LA grade C or D has objective erosive disease and by definition does not have functional heartburn. Grade A is where the two most often need disentangling, which is precisely where reflux monitoring earns its place.
Pearls & pitfalls
- A mucosal break needs a discrete line of demarcation from normal mucosa. Erythema, oedema, friability and increased vascularity are not breaks, and grading them as LA A is the commonest inflation of this classification.
- Assess in order: circumference, then fold continuity, then length. A 3 mm break bridging two fold tops is grade C, not grade A.
- There is no LA grade 0. A normal oesophagus is 'no erosive oesophagitis'.
- Grade on the worst finding, not the number of breaks. Twenty short non-bridging breaks are still grade A or B.
- Endoscopy on a proton pump inhibitor under-grades. Where the diagnosis matters, grade before starting acid suppression or after an adequate off-therapy interval.
- Grade A occurs in asymptomatic people and has the weakest interobserver agreement — treat it as supportive rather than diagnostic.
- Grades C and D confirm reflux disease, so a pH study to establish the diagnosis is unnecessary in that group.
- Repeat endoscopy after healing in grade C and D disease: severe erosions can conceal an underlying Barrett's segment.
- Record strictures, ulcers and Barrett's segment separately. Unlike Savary-Miller, this classification deliberately does not fold complications into the grade.
Critical actions
- Confirm the finding is a true mucosal break with a demarcation line before assigning any grade.
- Where possible, perform the diagnostic endoscopy off acid suppression, since treatment heals erosions and erases the finding.
- In grade C or D, treat with a proton pump inhibitor and arrange repeat endoscopy after healing to exclude underlying Barrett's oesophagus.
- In grade A or B with persisting diagnostic uncertainty, arrange reflux monitoring rather than relying on the grade.
- Record any stricture, ulcer or Barrett's segment separately from the grade, along with the Prague classification where columnar mucosa is seen.
- Consider long-term maintenance therapy in grade D, given the high relapse rate.
- Document which feature determined the grade, so that a later endoscopy is comparing like with like.
Why this score exists
The system's defining choice was to grade one thing only. Savary-Miller and its relatives had bundled strictures and Barrett's oesophagus into the severity scale, which conflated a complication of past disease with current inflammatory activity and made the grades mean different things to different endoscopists. Restricting the Los Angeles classification to mucosal breaks — and recording strictures, ulcers and Barrett's separately — is why it reproduces where the others did not. The second choice is subtler and more elegant: ranking fold continuity above absolute length. Estimating millimetres on a curved, moving luminal surface is genuinely hard, whereas seeing whether a break crosses from one fold top to the next is close to binary, so the more reproducible judgement was placed higher in the hierarchy. That is also why grade A, which depends entirely on a length estimate, is the grade endoscopists agree on least.
About the creator
First author, 1999 validation study
Led the validation of the Los Angeles classification and its clinical and functional correlates.
Co-author; also a principal author of the Prague C & M criteria
Central to the development of the Los Angeles classification within the international working group.
Co-author of the 1999 validation study.
Limitations
- Interobserver agreement is weakest at grade A, which depends on estimating millimetres on a curved luminal surface — and grade A is also the commonest finding.
- Grade A occurs in a proportion of asymptomatic people, so it is poor evidence of clinically significant reflux disease.
- Grades erosions only, and therefore says nothing about the majority of reflux patients, who have non-erosive disease and a normal endoscopy.
- Acid suppression heals erosions, so an endoscopy on therapy systematically under-grades and frequently misses erosive disease altogether.
- Does not incorporate strictures, ulcers or Barrett's oesophagus, which must be recorded separately — a deliberate design choice, but it means the grade alone does not describe severity of disease overall.
- Correlation between grade and symptom severity is imperfect in both directions; severe erosive disease can be asymptomatic, particularly in older patients.
- The 5 mm and 75% thresholds are consensus judgements rather than empirically derived cut-points.
If you are the patient
When acid from the stomach repeatedly washes into the gullet, it can wear away small patches of the lining. At endoscopy these appear as breaks, and doctors grade them from A to D depending on how extensive they are. Grade A means one or more small breaks under 5 mm across; grade B means a longer break; grade C means a break that stretches between the ridges inside the gullet; and grade D means breaks affecting three-quarters or more of the way around. The grade is useful for two reasons. Grades C and D are clear proof that acid reflux is causing the problem, so no further tests are needed to confirm it — treatment can simply start, with a repeat look later to check healing. Grade A is much less conclusive, because small breaks are sometimes found in people with no symptoms at all, so if the diagnosis really matters your doctor may suggest a test that measures acid directly. One practical point: acid-reducing medicines heal these breaks, so an endoscopy done while taking them may look normal even when reflux disease is present.
Frequently asked questions
What is the Los Angeles classification of oesophagitis?#
A system grading erosive oesophagitis from A to D based on mucosal breaks: grade A is breaks of 5 mm or less not bridging folds, B is breaks over 5 mm not bridging folds, C is breaks continuous between the tops of two or more folds involving under 75% of the circumference, and D is breaks involving 75% or more.
What counts as a mucosal break?#
An area of slough or erythema with a discrete line of demarcation from adjacent normal mucosa. Erythema alone, oedema alone, friability and increased vascularity do not qualify — grading those as LA A is the commonest way the classification is inflated.
Does LA grade A confirm reflux disease?#
Not reliably. Grade A is found in a proportion of asymptomatic people, has the weakest interobserver agreement in the system, and correlates loosely with pathological acid exposure. The Lyon consensus does not accept grade A as conclusive evidence, whereas grades C and D are accepted without further testing.
Is there an LA grade 0?#
No. The classification grades mucosal breaks, so a normal-appearing oesophagus is reported as no erosive oesophagitis rather than as grade 0. That finding is common and does not exclude reflux disease — non-erosive reflux disease is the most frequent phenotype.
How is a short break that crosses two folds graded?#
As grade C. Fold continuity outranks length in the hierarchy, so a 3 mm break that bridges the tops of two mucosal folds is grade C, not grade A. Circumferential involvement of 75% or more outranks both and gives grade D.
Should endoscopy be done on or off acid suppression?#
Off, where the diagnosis matters. Proton pump inhibitors heal erosions, so an endoscopy performed on therapy will under-grade and often shows nothing at all — which can lead to a patient with genuine erosive disease being labelled as having a normal oesophagus.
Why repeat endoscopy after healing in grade C and D?#
Because severe erosive disease can conceal an underlying Barrett's segment that only becomes visible once the erosions have healed. The repeat examination establishes whether columnar metaplasia is present and, if so, its Prague classification.
How does the LA classification differ from Savary-Miller?#
Savary-Miller placed strictures and Barrett's oesophagus in the severity scale alongside erosions, conflating complications of past disease with current activity and making grading unreproducible. The LA classification grades mucosal breaks only and records complications separately.
References
Original / primary reference
Guidelines and consensus
- Katz PO, Dunbar KB, Schnoll-Sussman FH, Greer KB, Yadlapati R, Spechler SJ. ACG Clinical Guideline for the Diagnosis and Management of Gastroesophageal Reflux Disease. Am J Gastroenterol. 2022;117(1):27-56.
- Gyawali CP, Yadlapati R, Fass R, et al. Updates to the modern diagnosis of GERD: Lyon consensus 2.0. Gut. 2024;73(2):361-371.