Acid reflux is a condition that occurs when acid from the stomach moves upward into the food pipe. The acid causes irritation of the tissue lining, which leads to heartburn - a burning sensation in the chest.
The American College of Gastroenterology estimate that over 60 million Americans experience heartburn a minimum of once a month. Some research indicates that over 15 million Americans may experience heartburn every day.
Heartburn that occurs more than twice a week can lead to a diagnosis of gastroesophageal reflux disease (GERD), which can cause ulcers and permanent damage if left untreated. GERD also increases the risk of esophageal cancer.
Heartburn is the most common symptom of acid reflux or GERD but a chronic cough is also a symptom.
Chronic coughing is usually defined as a cough that lasts for 8 weeks or longer.
Although chronic coughing is not a typical symptom of acid reflux, GERD is associated with at least 25 percent of cases of chronic cough, according to some research. Other research suggests GERD is a factor in 40 percent of people who have a chronic cough.
While a link exists between chronic cough and GERD, it does not mean that GERD is always the cause of the cough. Chronic cough is a common problem, and a person may simply have these two conditions at the same time.
How reflux leads to coughing
Of course, in some cases, chronic cough may be caused or made worse by acid reflux. There are two possible mechanisms to explain this occurrence.
The first suggests that a cough occurs as a reflexive action set off by the rising of stomach acid into the food pipe.
The second mechanism proposes that reflux moves above the food pipe and causes tiny droplets of stomach acid to land in the voice box or throat. This type of reflux is known as laryngeal pharyngeal reflux (LPR). LPR may lead to the development of a cough as a protective mechanism against the reflux.
LPR, also known as silent reflux or atypical reflux, is similar to GERD, although it frequently has different symptoms.
When stomach acid comes into contact with the vocal cords and throat, it can cause inflammation leading to symptoms such as:
- throat clearing
- the feeling that something is stuck in the throat
The amount of stomach acid needed to irritate the lining of the throat and voice box is quite small. Only 50 percent of those with LPR experience heartburn.
To diagnose GERD and an associated chronic cough, doctors will take a detailed case history and assess the individual's symptoms. It can be more difficult to diagnose a chronic cough in those experiencing LPR without heartburn.
People should keep in mind that in up to 75 percent of cases where a cough has been caused by GERD, there might be no gastrointestinal symptoms.
The best way to diagnose GERD is with pH monitoring. This test is used less often than diagnosis based on symptoms and case history, however.
The 24-hour pH test involves placing a probe through the nose into the food pipe to measure esophageal pH levels. A Bravo esophageal pH test is also available. Here, a small capsule is placed in the food pipe during an endoscopy for a specified period of time.
A doctor may also try a patient on proton pump inhibitors (PPIs), a type of medication for GERD. If coughing symptoms improve during this time, it can indicate the cough is related to acid reflux.
Treatment for a chronic cough caused by acid reflux aims to reduce the reflux that is causing or worsening the coughing. This is often done through medication.
Lifestyle and dietary changes are also quite effective, particularly for those with mild to moderate symptoms. In severe cases of reflux, surgery may be considered.
People with chronic cough caused by acid reflux can try making the following lifestyle changes to improve their symptoms:
- Maintaining a healthy body mass index (BMI): This can reduce some of the pressure on the stomach, lessening the amount of stomach acid forced up the food pipe.
- Wearing loose clothing: This reduces pressure on the stomach.
- Stopping smoking: Smokers are at a higher risk of developing GERD.
- Eating slowly and avoiding overeating: Large meals inhibit the closure of the lower esophageal sphincter (LES), allowing stomach acid to rise up into the food pipe.
- Not lying down after or during meals: People should wait for approximately 3 hours before lying down after meals.
- Elevating the head of the bed: Those with nighttime acid reflux could try raising the head of their bed with blocks or wooden wedges. Doing so may lessen the amount of rising acid.
Some foods and drinks trigger acid reflux. The most common offenders are:
- fried foods
- high-fat foods
- spicy foods
- tomatoes and tomato-based foods
Food triggers vary from person to person, so keeping a diary of food intake and symptoms can be a useful way for people to discover which foods contribute to symptoms.
Some common prescription and over-the-counter medications for acid reflux and associated symptoms include:
- Antacids: There are several antacids available over the counter. Baking soda is a common antacid found in the home.
- H-2-receptor blockers: These lower stomach acid production for up to 12 hours. They are available over the counter or on prescription.
- PPIs: These are stronger than H-2-receptor blockers, and work by blocking acid production for longer periods, allowing esophageal tissue time to heal. They are available over the counter or on prescription.
Most people with GERD and acid reflux will respond to lifestyle changes or medication, or a combination of both.
In more serious cases, surgical interventions may be considered necessary. Available surgeries include those to tighten the LES, or to insert a magnetic device to aid the function of the LES.
There are many other causes of chronic cough. Some research indicates that chronic cough has more than 20 causes, with more than one cause involved in 62 percent of cases.
Common causes include:
- respiratory tract infections
- chronic bronchitis
- postnasal drip
- tobacco use
- some medications such as ACE-inhibitors
When to see a doctor
If a cough persists for 3 weeks without improving, a doctor should be consulted.
Medical advice should also be sought if the cough is severe or gets worse, is accompanied by blood or chest pain, or if it is difficult to breathe.
A cough associated with other symptoms of acid reflux or LPR should also be seen by a doctor.