Causes and Risk Factors of Gastroesophageal Reflux Disease (GERD)

Drinking beer can lead to GERD.
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Gastroesophageal reflux disease (GERD) is caused by reflux of stomach acid into the esophagus when your lower esophageal sphincter (LES) is either weak or it relaxes when it shouldn't. Other potential causes can include obesity, smoking, certain medications, pregnancy, certain foods, and having a hiatal hernia. GERD can also be due to various conditions, including abnormal biologic or structural factors.

If you suffer from frequent heartburn, it's important that you consult with your physician to find the cause of your acid reflux and agree on a treatment plan.

Common Causes

There are a number of factors that can cause GERD. Sometimes the cause of your GERD can be complex and involve multiple factors.

Malfunctioning Lower Esophageal Sphincter (LES)
In most sufferers, acid reflux is due to a relaxation of the LES, which is responsible for closing and opening the lower end of the esophagus and acts as a pressure barrier against the contents of the stomach. If it's weak or loses tone, the LES will not close completely after food passes into your stomach. Stomach acid can then back up into your esophagus. The esophagus lining isn't the same as that of the stomach and isn't able to cope with acid as well as the stomach, so it's easily injured. It is this reflux of acid into the esophagus caused by malfunctioning of the LES that produces symptoms and potential damage to the esophagus.

Sometimes this malfunction is structural, but certain foods and beverages, drugs, and other factors can weaken the LES and impair its function.

Obesity
Being obese increases the pressure on your abdomen, making GERD symptoms worse. The exact link between GERD and obesity isn't fully understood, but being obese is considered both a potential cause and a risk factor for developing GERD.

Medications
There are various drugs, both over-the-counter and prescription, that can increase the risk for GERD, and worsen symptoms in those who already suffer from GERD because they cause the LES to relax or weaken.

Nonsteroidal anti-inflammatory drugs (NSAIDs) include aspirin, Motrin or Advil (ibuprofen), and Aleve (naproxen), and gastrointestinal side effects are common when taking them. These medications are usually associated with causing peptic ulcers, and can also make heartburn and esophageal irritation worse. In people who already have GERD, they may increase the severity of symptoms and in people who don't, long-term use of NSAIDs may contribute to developing GERD.

Certain prescription drugs may also cause or worsen the symptoms of GERD. It's important to consult your doctor if you start experiencing any symptoms while on medication. Here are some common culprits:

  • Calcium channel blockers, which are used to treat high blood pressure and heart disease
  • Anticholinergics, used in drugs that treat urinary tract disorders, allergies, and glaucoma
  • Beta-adrenergic agonists, used for asthma and obstructive lung diseases
  • Tricyclic antidepressants such as amitriptyline, Tofranil (imipramine), and Pamelor (nortriptyline)
  • Antihistamines, used for allergies
  • Prescription painkillers like codeine and medications containing acetaminophen and hydrocodone
  • Progesterone
  • Quinidine, an antimalarial drug used to treat heart arrhythmias and malaria
  • Sedatives and benzodiazepines such as Valium (diazepam)
  • Theophylline, used in bronchodilators for asthma, chronic bronchitis, and other lung diseases
  • Diazepam, which is used to treat seizures
  • Dopamine, used in Parkinson's disease
  • Bisphosphonates used to treat osteoporosis.
  • Antibiotics like tetracycline
  • Potassium supplements
  • Iron supplements

Smoking
Smoking or breathing in secondhand smoke is also considered both a cause and a risk factor for developing GERD.

There are many ways in which smoking can lead to heartburn, such as decreasing the amount of saliva you produce, causing your stomach to empty more slowly, and creating more stomach acid. Smoking cessation is probably one of the best things you can do to lessen your symptoms or lower your risk of developing reflux in the first place.

Hiatal Hernia
Having a hiatal hernia may cause acid reflux. A hiatal hernia occurs when the upper part of your stomach is above the diaphragm, the muscle wall that separates the stomach from the chest. The diaphragm helps the LES keep acid from coming up into the esophagus. When a hiatal hernia is present, it's easier for the acid to come up because the pressure on the LES is lower, causing reflux. A hiatal hernia can happen in people of any age; many otherwise healthy people over 50 have a small one.

Impaired Stomach Function
GERD sufferers may have abnormal nerve or muscle function in the stomach which, in turn, causes food and stomach acid to be digested too slowly. This will cause a delay in the stomach emptying its contents, increasing pressure in the stomach and increasing the risk of acid reflux.

Motility Abnormalities
In normal digestion, food is moved through the digestive tract by rhythmic contractions called peristalsis. If you suffer from a digestive motility abnormality, these contractions are abnormal. This abnormality can be due to one of two causes: A problem within the muscle itself, or a problem with the nerves or hormones that control the muscle's contractions. Problems in peristalsis in the esophagus are common in GERD, although it's not clear if such occurrences are a cause or a result of the long-term effects of GERD.

Pregnancy
The increase of the hormones estrogen and progesterone during pregnancy relax the LES, plus your expanding belly puts more pressure on your abdomen, so it's pretty normal for pregnant women to experience heartburn, which can lead to GERD.

Asthma
More than 75 percent of asthmatic sufferers are believed to also have GERD. No one really knows whether asthma causes GERD, or if it's the other way around. There are a couple of reasons why the two conditions are associated with each other. The first is that the coughing that accompanies asthma attacks may lead to changes in chest pressure, which can trigger reflux. Then there is the fact that certain asthmatic medications dilate the airways, relaxing the LES and leading to reflux. Both diseases worsen the other's symptoms, but treating GERD usually helps asthma symptoms as well.

Foods
There is an ongoing debate as to whether certain foods can cause heartburn. If you rarely have heartburn, food usually isn't associated with an attack, but if you have it on a recurring basis you may notice that some foods seem to trigger it for you. Some types of foods stimulate acid production and some relax the LES.

Foods That Relax the Lower Esophageal Sphincter
Normally, the LES, the valve between your esophagus and stomach, closes tightly to keep food and stomach acid in your stomach. If it relaxes when it shouldn't, food and stomach acid come back up into your esophagus and you may feel heartburn.

The following are examples of foods that can relax the LES:

  • Fried (greasy) foods
  • High-fat meats
  • Butter and margarine
  • Mayonnaise
  • Creamy sauces
  • Salad dressings
  • Whole-milk dairy products
  • Chocolate
  • Peppermint
  • Caffeinated beverages like soft drinks, coffee, tea, and cocoa

Foods That Stimulate Acid Production
Heartburn may also occur when your stomach produces too much acid, which backs up into your esophagus. Foods that may stimulate acid production and increase heartburn are:

  • Caffeinated beverages
  • Carbonated beverages
  • Alcohol
  • Spicy foods
  • Black pepper
  • Citrus fruit and juices like orange or grapefruit
  • Tomato juice

Salt
Studies have shown that a diet that's high in sodium may cause acid reflux, which can lead to GERD. However, in healthy people, an excessively salty diet doesn't seem to increase acid reflux. More studies need to be done, but at the very least, salt may be a trigger for certain people to cause heartburn. The only way to know for sure is to try limiting your salt intake to see if it makes a difference.

Genetics

Multiple studies have shown that there is a genetic component in many cases of GERD, which may sometimes be because of inherited muscular or structural problems in the esophagus or stomach. One study found that a DNA variation called GNB3 C825T was present in every person in the study with GERD, but it wasn't present in the control group in the study who did not have GERD.

Genetic factors also appear to play a big role in a patient's susceptibility to Barrett's esophagus, a precancerous condition caused by very severe gastroesophageal reflux. One study found that GERD, Barrett's esophagus, and esophageal cancer all have a significant genetic overlap.

Scientists believe that developing GERD takes a combination of genetic and environmental factors, as well as lifestyle choices. Just because your parent or sibling has GERD doesn't mean you necessarily will, though it's more likely when someone else in your family has it. More research needs to be done on the genetic component so that diagnosis and treatment for GERD can be even more effective and targeted.

Risk Factors

Many adults experience heartburn and anyone at any age can develop GERD. Here are some factors that may increase your risk.

Scleroderma
This autoimmune disorder, in which the immune system attacks healthy cells in the body, increases your risk for GERD. Many people with scleroderma also have GERD because the esophagus is the most commonly affected organ in scleroderma.

Asthma and COPD
Doctors may not completely understand the relationship between asthma and GERD, but most experts do agree there is an important connection. Some experts hypothesize that the coughing that accompanies asthmatic attacks can cause changes in pressure in the chest, which then can trigger reflux. Certain drugs for asthma that dilate the airways may also relax the LES and contribute to GERD. Likewise, GERD has been associated with a number of other upper respiratory problems and may be a cause of asthma that starts in adulthood, rather than a result.

Chronic obstructive pulmonary disease (COPD) also puts you at a higher risk of developing GERD and having GERD may make your COPD symptoms worse.

Diabetes
People with diabetes, especially Type 1 diabetes, often develop a condition called gastroparesis. This condition is characterized by delayed stomach emptying. The pressure within the stomach can increase, which in turn can result in reflux, making you more prone to develop GERD.

Celiac Disease
People with celiac disease seem to have a much higher rate of GERD than the general population, especially when they're newly diagnosed. Studies have shown that a gluten-free diet significantly reduces symptoms of GERD. Experts aren't sure whether consuming gluten causes GERD or if GERD is an associated condition of celiac disease. Sometimes GERD doesn't occur until after a person is diagnosed with celiac disease, which indicates that there may be something else causing it.

Lifestyle Risk Factors

There are certain lifestyle risk factors associated with developing GERD. These may be factors you can change or control.

Obesity
Obesity is both a cause and a risk factor for developing GERD. Excess weight around your belly area, in particular, puts you at a higher risk for developing GERD and its associated complications such as Barrett's esophagus and esophageal cancer. Losing weight can help decrease your GERD symptoms.

Smoking
Like obesity, smoking is both a cause and a risk factor for developing GERD. Smoking impairs the function of the LES, increases the secretion of acid, and causes you to produce less saliva, all causes of GERD.

Eating Patterns
Eating big meals all at once, especially if you lie down afterward, and eating right before bed all increase your risk of developing acid reflux, which can lead to GERD. Try eating smaller, more frequent meals and don't eat for several hours before bedtime.

Hormone Replacement Therapy
Women who are on hormone replacement therapy are more likely to develop GERD. The longer you're on it and the higher the dose of estrogen, the higher the risk. 

Sources:

Kahrilas PJ. Pathophysiology of Reflux Esophagitis. UpToDate. Updated March 6, 2018.

National Institute of Diabetes and Digestive and Kidney Diseases. Eating, Diet, & Nutrition for GER & GERD. Published November 2014.

National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms & Causes of GER & GERD. Published November 2014.

Mayo Clinic Staff. Gastroesophageal Reflux Disease (GERD). Mayo Clinic. Updated March 9, 2018.

Ping W, Xiao-Hu Z, Zi-Sheng A, et al. Dietary Intake and Risk for Reflux Esophagitis: A Case-Control Study Gastroenterology Research and Practice. 2013;2013:691026. doi:10.1155/2013/691026.