Before you can understand what causes acid reflux, or gastroesophageal reflux disease (GERD), you need to learn the basic anatomy of the esophagus. The esophagus is a muscular tube that connects the throat to the stomach. Food travels down the esophagus and into the stomach, where stomach acid breaks the food up and sends it to the intestines for further digestion. The muscular tube has an upper esophageal sphincter and a lower esophageal sphincter. These valves work to keep food out of the airway and in the stomach. When the lower esophageal sphincter closes, it puts pressure on the stomach so food and stomach acids cannot back up into the esophagus.
When something causes the lower esophageal sphincter to relax, this causes acid to back up from the stomach into the esophagus. This results in the symptoms of acid reflux and GERD. GERD, also called heartburn or acid indigestion, causes burning pain behind the breast bone, in the middle of the chest and in the middle of the abdomen. It may also cause asthma symptoms, difficulty swallowing or dry cough, according to the National Digestive Diseases Information Clearinghouse. Identifying acid reflux triggers will help you avoid the major causes of acid reflux and eliminate these symptoms.
Some foods trigger the symptoms of acid reflux. These foods have a high level of acidity, which results in relaxation of the lower esophageal sphincter. If you have acid reflux, avoid citrus fruits, caffeinated beverages, fatty foods, alcoholic drinks, fried foods, spicy foods, garlic, tomato-based foods (e.g. salsa), chocolate and mint-flavored foods.
Overweight and obesity increase the risk for gastroesophageal reflux disease because the extra weight causes the lower esophageal to weaken. WebMD reports that eight out of nine studies found a relationship between body mass index (BMI) and gastroesophageal reflux. In these eight studies, GERD symptoms worsened as BMI increased. People with higher body mass indexes may also consume more of the foods that cause GERD to worsen, including fatty foods and spicy foods.
Saliva helps to neutralize stomach acid, which prevents the acid from backing up into the esophagus. Smokers produce up to 50 percent less saliva than non-smokers, according to Dr. Ronen Arai, a gastroenterologist at the University of Miami School of Medicine. Dr. Arai recommends quitting smoking entirely to relieve the symptoms of GERD.
A hiatal hernia occurs when the lower esophageal sphincter and the upper portion of the stomach move above the diaphragm. This allows the lower esophageal sphincter to open and allow stomach acid to back up. Hiatal hernias occur more frequently in obese people and people over the age of 50.
HealthCentral reports that acid reflux occurs in up to 50 percent of all pregnancy women. Two major changes promote acid reflux during pregnancy. The first is an increase in hormone levels, particularly estrogen and progesterone. These hormone levels increase during fetal development and remain high through pregnancy. This decreases the pressure the lower esophageal sphincter places on the stomach, which allows stomach acid to back up into the esophagus. The developing fetus also puts pressure on the abdominal organs, which also promotes acid reflux. Several lifestyle changes can reduce the symptoms of GERD during pregnancy. They include elevating the head of the bed, avoiding food causes of acid reflux, chewing gum, taking antacids and eating smaller meals.
In some cases of GERD, the affected person has impaired stomach function. This dysfunction involves nerve or muscle problems, which cause the stomach to digest food more slowly than normal. When there is a delay in stomach emptying, the pressure in the stomach increases. This increases the risk of GERD symptoms.
Prescription and OTC Medications
Some medications either worsen GERD symptoms or increase the risk for developing GERD. Nonsteroidal anti-inflammatory drugs, more commonly known as NSAIDs, worsen GERD symptoms. People who take NSAIDs are twice as likely to have GERD as people who do not take NSAIDs. Examples of NSAIDs include ibuprofen, aspirin and naproxen. Other medications that cause GERD include dopamine, sedatives, potassium, antibiotics, calcium channel blockers and drugs used to treat allergies and glaucoma.
There is a clear link between asthma and GERD, but scientists do not know if asthma is one of the causes of acid reflux, or if the acid reflux causes asthma symptoms. One theory, according to About.com guide Sharon Gillson, is that the coughing caused by asthma changes the pressure in the chest. This leads to a weakened LES and the opportunity for acid to back up in the esophagus. Some asthma medications also increase the risk for GERD.
GERD prevention involves avoiding some of the major causes of acid reflux. If you are overweight or obese, reduce your weight through diet and exercise. Try to lose one to two pounds per week, since doctors recommend that you lose weight slowly. Avoid the foods that cause GERD symptoms, especially if you notice one or two foods cause acid reflux flares. If you have asthma, keep it under control by following your doctor’s treatment plan. Take all medications as prescribed to control asthma coughing and airway irritation. If you smoke, quit. This will prevent GERD symptoms and reduce the risk for some of the most serious cardiovascular and respiratory diseases. Discuss your options for preventing GERD during pregnancy, as pregnant women cannot take some drugs.
National Digestive Diseases Information Clearinghouse: Heartburn, Gastroesophageal Reflux (GER) and Gastroesophageal Reflux Disease (GERD)
WebMD: Obesity, Acid Reflux Linked?
Nexium Research: Can Smoking Cause GERD?
MayoClinic.com: Hiatal Hernia
HealthCentral: 8 Ways to Treat Acid Reflux During Pregnancy
About.com: Causes of Gastroesophageal Reflux Disease