What is Silent Reflux?

Silent reflux, also known as laryngopharyngeal reflux (LPR), is a kind of reflux that causes respiratory symptoms such as hoarseness, cough, and asthma.

Most people know the typical acid reflux symptoms first-hand, or they have at least heard of them in TV advertisements for reflux medication. Acid reflux typically causes heartburn, or a feeling like cramps and pressure in the chest.

The respiratory symptoms of silent reflux, however, are more difficult to recognize. Silent reflux causes rather unspecific symptoms, which is why many people do not realize that their symptoms are caused by silent reflux. 

The term “silent reflux” stems from the fact that the symptoms are difficult to attribute to the disease. The symptoms can build up over a long time without anybody realizing the true cause. As a result, the disease can stay “silent” for a long time before being diagnosed and treated correctly. Even for most physicians, the diagnosis is very difficult, which is why many patients see many doctors over the years before they get their diagnosis for silent reflux.

Silent Reflux: A Wide Range of Symptoms

Silent reflux can cause a wide range of symptoms. The assessment of symptoms also plays a crucial role in the diagnosis of the condition. Our silent reflux online test helps you to find out whether your symptoms point towards silent reflux.

Symptoms of silent reflux include[1]

The article about silent reflux symptoms describes the signs of the condition in more detail.

Causes and Treatment of Silent Reflux

The damage caused by silent reflux is based on two factors:

  1. The immediate damage caused by acid reflux reaching the airways
  2. Enzymes from the stomach (pepsins) that are carried along with the stomach acid, irritating the mucous membranes of the throat and airways.

A successful treatment strategy has to address both of these factors.

Pepsin is a critical part of the equation to understand. Pepsin is a stomach enzyme that digests proteins. It only plays a minor role in classic reflux symptoms such as heartburn, but it is essential to silent reflux. While the esophagus is well protected against pepsin, the airways are not. Refluxed pepsin attaches itself to the tissues of the respiratory tract, and there it continues doing its job: digesting proteins. In the process, it damages the cells in our airways, causing inflammation and the symptoms of silent reflux.

1) Preventing Reflux at Its Source

Think of the esophagus as a one-way street. Food is supposed to go down only, but nothing should go up – at least if we ignore vomiting.

The esophagus contains two valves (sphincters). Essentially, those sphincters are muscular rings that enclose the esophagus. One sphincter sits at each end of the esophagus.[3]

The most important when it comes to reflux is the lower esophageal sphincter (LES), which sits directly above the stomach. The LES has a tough job, as eating increases the pressure in the stomach – even drastically if someone overeats.

The LES needs to squeeze tight to keep everything constantly in the stomach. Sometimes, though, it fails to stay shut, and reflux occurs. Remember that at the end of the day, the LES is just a muscle. It becomes particularly prone to allowing reflux if it gets overworked constantly by overeating. It gets tired, and even damaged over time. Some people happen to be born with a weak LES and are therefore naturally prone to reflux.

To prevent reflux, you must avoid things that increase the pressure in the stomach too much. Furthermore, you need to avoid anything that weakens the sphincter.

Diet

Reflux is often caused, or at least worsened, by eating habits.

As a result, making dietary changes can often lead to rapid improvements in reflux symptoms.

Large meals increase stomach pressure, thereby straining the LES. Eating smaller meals, conversely, reduces the stress on the LES.

It is especially important to avoid eating before bedtime. There should be about 4 hours between the last meal and going to bed. During the day, gravity helps to keep the stomach contents inside the stomach. Once lying down, though, the stomach contents press against the LES, which is why, for many people, reflux is the worst at night.

Certain foods are known to relax the LES, which will then have trouble keeping shut and so will allow reflux more often. They include chocolate, caffeine (mainly coffee and tea), and alcohol.[4],[5] High-fat meals, particularly fried foods, are another trigger for many people.[6]

I will write more about diet later in the article, as this is what I know interests many of my readers the most.

Medication

For heartburn, there are medications that can give patients rapid and significant improvement in their symptoms, in particular proton-pump inhibitors (PPIs) such as Prilosec and Nexium.

Many physicians who are not well versed with silent reflux assume that because PPIs help with “normal” reflux, they will also help with silent reflux. However, study data from recent years shows that this is not the case, and in fact PPIs work no better than placebo for silent reflux.[7]

The most likely reason is that silent reflux is primarily caused by the pepsin in the refluxed stomach acid, while classical reflux is mostly caused directly by the stomach acid. This is why medication that reduces acidity helps with heartburn, but not so much with silent reflux. In spite of this, physicians diagnose patients with silent reflux and send them home with nothing more than a prescription for a PPI, with the result that many patients do not get better.

There is a lot of disagreement in the medical community about the exact role acid-suppressing medication should play in the treatment of silent reflux. It is an ongoing debate and far from resolved. My conclusion is that acid-suppressing medication might play a supportive role in the treatment, but it cannot be the fundamental pillar.

Surgery

Nearly everybody with silent reflux gets better on diet and behavioral changes alone. Only in a fraction of patients is the LES so weak that it needs surgery to strengthen it. The most established surgery for reflux is the Nissen fundoplication. In this procedure, the upper part of the stomach is wrapped around the LES to tighten it up, so preventing the reflux from rising towards the esophagus.

Nissen fundoplication is effective for many silent reflux patients, but it also bears the risk of complications.[8] ,[9] A bloated belly is a common side effect that occurs in 10% of Nissen fundoplication patients.[10] The surgery can also cause swallowing difficulties. Another danger of the surgery is vagus nerve damage.[11],[12],[13],[14] The vagus nerve is a very long cranial nerve that reaches from the brain down to the stomach and controls the digestive system. As a result, damage to this nerve can cause digestive problems.

Because of the common side effects of Nissen fundoplication and other surgical approaches, surgery is only recommended when other measures have failed to provide relief. Moreover, surgery has a lower success rate for silent reflux than for esophageal reflux.

Our article about surgical procedures for silent reflux provides more detailed information.

2) Preventing the Reactivation of Pepsin

Another way to reduce silent reflux symptoms is to reduce the harm that pepsin can do.

As mentioned before, pepsin is a stomach enzyme that digests proteins. In silent reflux, it reaches the airways and damages the cells there, causing inflammation.

However, the amount of harm pepsin can do depends on the acidity level (pH). The more acidic the environment, the more aggressive pepsin becomes, which makes sense as pepsin is supposed to only be active in the stomach.

One thing that can reduce the pH levels in the airways is acid reflux itself.

Another important factor, however, is diet.

Acidic foods passing down the throat increase the activity of pepsin, and as a result, pepsin will cause more symptoms.[15] The problem is that the cells of the mucous membranes mainly consist of proteins, and it is therefore not surprising that pepsins can cause severe damage outside the stomach.

Pepsin is an essential part of our digestive system. There are no drugs that work against pepsin, but it is possible to prevent the reactivation of pepsin in our airways by eliminating acidic foods and drinks from our diet.[16],[17],[18]

Our article about diet for silent reflux provides more information.


References

[1] Vaezi MF, Hicks DM, Abelson TI, Richter JE. Laryngeal signs and symptoms and gastroesophageal reflux disease (GERD): a critical assessment of cause and effect association. Clin Gastroenterol Hepatol. 2003;1(5):333–44.

[2] Lechien JR, Huet K, Khalife M, et al. Impact of laryngopharyngeal reflux on subjective and objective voice assessments: a prospective study. J Otolaryngol Head Neck Surg. 2016;45(1):59.

[3] Brown J, Shermetaro C. Laryngopharyngeal reflux. [Updated 2019 Jun 4]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2019 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK519548/

[4] Wright LE, Castell DO. The adverse effect of chocolate on lower esophageal sphincter pressure. Am J Dig Dis. 1975;20(8):703–7.

[5] Lohsiriwat S, Puengna N, Leelakusolvong S. Effect of caffeine on lower esophageal sphincter pressure in Thai healthy volunteers. Dis Esophagus. 2006;19(3):183–8.

[6] Nebel OT, Castell DO. Fat inhibition of the lower esophageal sphincter: a mechanism for fatty food intolerance. Ann Intern Med. 1972;76(5):860.

[7] Reimer C, Bytzer P. Management of laryngopharyngeal reflux with proton pump inhibitors. Ther Clin Risk Manag. 2008;4(1):225–233.

[8] van der Westhuizen L, Von SJ, Wilkerson BJ, et al. Impact of Nissen fundoplication on laryngopharyngeal reflux symptoms. Am Surg. 2011;77(7):878–82.

[9] Carroll TL, Nahikian K, Asban A, Wiener D. Nissen fundoplication for laryngopharyngeal reflux after patient selection using dual pH, full column impedance testing: a pilot study. Ann Otol Rhinol Laryngol. 2016;125(9):722–8.

[10] Carlson MA, Frantzides CT. Complications and results of primary minimally invasive antireflux procedures: a review of 10,735 reported cases. J Am Coll Surg. 2001;193(4):428–39.

[11] Lindeboom MY, Ringers J, van Rijn PJ, Neijenhuis P, Stokkel MP, Masclee AA. Gastric emptying and vagus nerve function after laparoscopic partial fundoplication. Ann Surg. 2004;240(5):785–790.

[12] van Rijn S, Roebroek YG, Conchillo JM, Bouvy ND, Masclee AA. Effect of vagus nerve injury on the outcome of antireflux surgery: an extensive literature review. Dig Surg. 2016;33(3):230–9.

[13] van Rijn S, Rinsma NF, van Herwaarden-Lindeboom MY, et al. Effect of vagus nerve integrity on short and long-term efficacy of antireflux surgery. Am J Gastroenterol. 2016 Apr;111(4):508–15.

[14] DeVault KR, Swain JM, Wentling GK, Floch NR, Achem SR, Hinder RA. Evaluation of vagus nerve function before and after antireflux surgery. J Gastrointest Surg. 2004;8(7):881–7.

[15] Johnston N, Dettmar PW, Bishwokarma B, Lively MO, Koufman JA. Activity/stability of human pepsin: implications for reflux attributed laryngeal disease. Laryngoscope. 2007;117(6):1036–9.

[16] Koufman JA. Low-acid diet for recalcitrant laryngopharyngeal reflux: therapeutic benefits and their implications. Ann Otol Rhinol Laryngol. 2011;120(5):281–7.

[17] Koufman JA, Huang S, Gelb M. Dr. Koufman’s Acid Reflux Diet: With 111 All New Recipes Including Vegan & Gluten-Free: The Never-Need-to-Diet-Again Diet. Katalitix. 2015.

[18] Koufman JA, Stern J, Bauer MM. Dropping Acid: The Reflux Diet Cookbook & Cure. Reflux Cookbooks; 1st ed. 2010.

Gerrit Sonnabend
 

Gerrit is a German data scientist & medical publisher. His formal education is in qualitative research. He had severe reflux himself. Read more about him here.