Silent Reflux (LPR): What It Is, Why It's Missed, and How to Confirm It
Laryngopharyngeal reflux — silent reflux — affects millions of people who never experience typical heartburn. Instead it causes persistent throat symptoms that are routinely misdiagnosed as allergies, infections, or stress. This guide explains what's really happening, and what you can do about it.
Simple home saliva test · No GP referral required · CE-IVD certified diagnostic
What Is Silent Reflux?
Silent reflux — known medically as laryngopharyngeal reflux, or LPR — is a condition in which the contents of the stomach travel upwards past the oesophagus and reach the throat, voice box (larynx), and airways. Unlike typical acid reflux or GORD, it often causes little or no heartburn, which is why so many people suffer for years without ever suspecting reflux is the cause.
The term "silent" refers to the absence of the classic burning sensation that most people associate with reflux. Instead, the stomach contents — including the digestive enzyme pepsin — reach the delicate tissues of the pharynx and larynx, causing inflammation and a range of symptoms that seem entirely unrelated to digestion.
LPR is classified as extra-oesophageal reflux disease (EORD or EERD), because the reflux extends beyond the oesophagus into the extra-oesophageal regions. It is thought to account for up to 10% of all outpatient ENT consultations, and is significantly underdiagnosed because its symptoms closely mimic other common conditions.
The connection between reflux and laryngeal damage was established in the early 1990s, but our modern understanding of why LPR behaves so differently from GORD — and why acid-suppressing drugs so often fail — emerged from research conducted over the following decades. Central to that understanding was the work of Professor Peter Dettmar, founder of Peptest and a pioneering researcher at the University of Hull, whose studies on pepsin activity and stability (conducted with colleagues including Dr Nikki Johnston at the Medical College of Wisconsin) established that pepsin — not acid — is the primary agent responsible for tissue damage in LPR. That body of research transformed how the condition is understood and continues to shape clinical thinking worldwide.
- Also called laryngopharyngeal reflux (LPR), extra-oesophageal reflux, or atypical reflux
- Up to 10% of ENT outpatient consultations involve LPR
- Up to 50% of people with LPR do not experience heartburn
- The primary damaging agent is pepsin, not acid
- PPIs (acid-suppressing drugs) are often ineffective for LPR
- Gaviscon Advance is the only licensed LPR treatment in the UK
- Peptest detects pepsin in saliva — the direct biomarker of reflux
Silent Reflux (LPR) vs Acid Reflux (GORD)
Many people — and clinicians — confuse LPR with standard acid reflux. They share a common origin, but are distinct conditions with different symptoms, diagnostic challenges, and treatment responses.
| GORD / Acid Reflux | LPR / Silent Reflux | |
|---|---|---|
| Where reflux reaches | Lower oesophagus | Throat, larynx, airways |
| Heartburn | Common, often severe | Absent in up to 50% of cases |
| Main damaging agent | Acid | Pepsin (enzyme) |
| Primary symptoms | Heartburn, regurgitation | Throat clearing, hoarseness, chronic cough, globus |
| Response to PPIs | Usually good | Often poor — randomised trials show no overall benefit |
| Diagnosis | Endoscopy, pH monitoring, symptom history | No definitive standard — Peptest detects pepsin directly |
| First-line treatment (UK) | PPIs, lifestyle changes | Gaviscon Advance, diet & lifestyle changes |
Symptoms of Silent Reflux
LPR produces a distinctive set of throat and voice symptoms — each with a specific mechanism rooted in pepsin-induced laryngeal inflammation. Because heartburn is so often absent, these symptoms are routinely attributed to allergies, infections, or stress rather than reflux. The most common include:
For clinical detail on each symptom — including the specific mechanism by which pepsin causes it, and why standard treatments so often fail — read our full symptom guide.
Read the Full LPR Symptom Guide — All 14 Symptoms Explained →Why Silent Reflux Is So Often Missed
LPR is one of medicine's most frequently misdiagnosed conditions — and this isn't a failure of modern medicine so much as a consequence of how unusual the condition is. There are several reasons it slips through the net so often.
Symptoms don't suggest the digestive system. When you go to your GP with a persistent cough, hoarse voice, or feeling of something stuck in your throat, reflux is rarely the first thing that comes to mind. You'll most likely be investigated for allergies, asthma, a vocal cord problem, or a post-viral condition. All of these are reasonable first steps — but if LPR is the underlying cause, none of those treatments will work.
There is no heartburn to flag it. In GORD, the symptom of heartburn is a direct pointer to the oesophagus and stomach. With LPR, that signpost is absent. Up to half of all LPR patients report no heartburn at all, which is why neither the patient nor the clinician naturally considers a digestive cause for their symptoms.
The standard acid-reflux tests often miss it. Endoscopy and conventional 24-hour pH monitoring measure acid in the oesophagus. But in LPR, the problem is happening higher up — in the throat and larynx. Many LPR patients have normal endoscopy findings, which can falsely reassure both patient and clinician that reflux isn't the issue.
PPIs are prescribed and appear to fail. Because LPR is often treated empirically with proton pump inhibitors (PPIs), and because PPIs are genuinely ineffective for many LPR patients (multiple randomised controlled trials have found no overall benefit), the failure of PPI treatment leads to the conclusion that it isn't reflux — rather than the correct conclusion, which is that LPR requires a different approach.
Symptoms overlap with more familiar conditions. Chronic cough can be allergy, asthma, or post-viral. Hoarseness can be a vocal cord nodule or overuse. Globus can be anxiety. Post-nasal drip can be sinusitis. Each of these diagnoses can be pursued for months or years while LPR continues undetected and the underlying damage continues.
The Role of Pepsin in LPR
The primary agent of tissue damage in LPR is not acid — it is pepsin, the digestive enzyme your stomach produces to break down food. Research conducted by Professor Peter Dettmar and Dr Nikki Johnston (Johnston & Dettmar, Laryngoscope 2007) established that pepsin is stable at the pH of the larynx, remains enzymatically active at that level, and can be absorbed by laryngeal cells and cause damage from within. This is why symptoms often persist after acid-suppressing treatment.
For the full science — including the endocytosis mechanism, dietary reactivation, why PPIs fall short, and the world's first pepsin-inhibiting drug now in Phase II trials — see our dedicated science page.
How Is Silent Reflux Diagnosed?
Confirming LPR is harder than it sounds. Standard reflux tests — endoscopy, 24-hour pH monitoring — are designed for GORD and routinely return normal results in LPR patients, because they measure acid in the oesophagus rather than pepsin reaching the throat. Laryngoscopy can identify signs of laryngeal inflammation, but the findings are non-specific and can occur with other conditions.
Peptest takes a fundamentally different approach: it detects pepsin — the enzyme biomarker of reflux — directly in a saliva sample. Because pepsin is only produced in the stomach, its presence in saliva is objective evidence that reflux has reached the throat. In the largest UK study (n=1,033 patients across five NHS voice clinics), Peptest demonstrated 100% specificity — every positive result confirmed reflux.
Standard Tests
pH monitoring, endoscopy, and laryngoscopy are designed for GORD. They measure acid in the oesophagus — not pepsin in the throat. Many LPR patients are told their results are normal.
Peptest — Salivary Pepsin Detection
Detects pepsin directly in saliva. Non-invasive, home collection, results in 48 hours. CE-IVD certified. 100% specificity in the largest UK clinical study.
How Peptest Works
Peptest is a CE-IVD certified lateral flow immunoassay that detects and quantifies pepsin — the biomarker of reflux — in expectorated saliva. It was developed by Professor Peter Dettmar, a world-leading pepsin researcher, and is manufactured at the RD Biomed laboratory at Castle Hill Hospital, Hull.
Order Your Kit
Order online at peptest.co.uk. No GP referral is required. Your kit is dispatched with free UK delivery, typically arriving the next working day. The kit contains saliva collection tubes, sample preservation solution, and full instructions.
Collect Your Samples
You collect up to three saliva samples at home — ideally on waking, after a meal, and at the time of worst symptoms. The sample procedure takes a few minutes. Samples are preserved immediately in the tubes and posted to the laboratory using the prepaid envelope provided.
Laboratory Analysis
Samples are analysed at the UK laboratory using the Peptest lateral flow immunoassay, with results read digitally for accuracy. The test uses antibodies specific to human pepsin to detect and quantify its presence. Results are typically reported within 48 hours of sample receipt.
Receive Your Results
You receive a detailed results report showing pepsin concentration from each sample, together with a clinical interpretation. A letter is also generated for your GP, explaining the result and making treatment recommendations. This gives you objective evidence to share with your doctor.
Treating Silent Reflux — the Evidence-Based Approach
LPR requires a fundamentally different treatment strategy from GERD. Because the primary damaging agent is pepsin — not acid — treatment must prevent pepsin from reaching the throat, not just suppress stomach acid.
Gaviscon Advance — the only UK-licensed LPR therapeutic — forms a physical raft that traps pepsin before it reaches the throat. More effective for LPR than PPIs because it targets the mechanical cause.
Reducing acidic foods prevents pepsin reactivation in laryngeal tissue — a distinct mechanism from GERD dietary advice. Combined with positional changes and meal timing, this addresses reflux frequency directly.
Retesting at 8–12 weeks provides objective evidence of whether pepsin has been eliminated. No other non-invasive test measures treatment response at the molecular level.
Our dedicated treatment guide covers the full evidence — why PPIs often fail, how alginates work, dietary reactivation of pepsin, and how to monitor your response with Peptest.
Read the Full LPR Treatment Guide →Frequently Asked Questions About Silent Reflux
Get Objective Evidence — Not Just a Theory
If you've been dealing with chronic throat symptoms, a persistent cough, or a hoarse voice with no satisfying explanation, Peptest gives you a clinical answer. A simple saliva test, processed in a UK laboratory, with results in 48 hours — and a report you can take to your doctor.
Order Peptest Now £79.95 · Free UK Delivery · No GP Referral NeededCE-IVD Certified · ISO 13485:2016 · UK Laboratory · Used in 40+ Countries