Causes of gastroesophageal reflux
GERD is a digestive disorder involving the lower esophageal sphincter (LES), the muscle joining the esophagus and stomach. This muscle serves as a barrier that shields the esophagus from stomach acid flowing backward. Under normal conditions, the LES works like a gate - opening to let food pass into the stomach, then closing to keep food and acidic stomach juices from washing back up into the esophagus.
The LES is a complex ring of smooth muscle governed by nerves and various hormones, so dietary substances, drugs, and nervous system factors can all interfere with how it works. Gastroesophageal reflux happens when the LES weakens or relaxes at the wrong moment, letting stomach contents rise into the esophagus. Scientists do not always know exactly why this occurs, but they have identified several contributing factors.
Digestive abnormalities. A malfunctioning LES is not the only digestive problem behind reflux and heartburn. If the stomach muscles do not contract properly, the stomach may empty more slowly, raising the odds that acid will back up into the esophagus. Esophageal contractions that would normally sweep refluxed acid away can also fall short. The esophageal lining may lose some of its ability to resist damage, or saliva production - which neutralizes acid - may drop.
Weight. Carrying extra weight raises the risk of frequent GERD symptoms. Even when a person's body mass index (BMI, a ratio of weight to height) stays within the normal range, gaining weight can bring on heartburn. The added weight puts pressure on the stomach and pushes its contents upward.
Pregnancy. Pregnancy can promote GERD, both because of hormonal shifts and because the enlarging uterus presses against nearby organs.
Age. With age, esophageal contractions and the LES muscles can weaken. Because the esophagus may also grow less sensitive to acid over the years, reflux does not always produce heartburn in older adults; nausea or vague chest discomfort may appear instead.
Smoking. Smoking irritates the digestive tract, and nicotine relaxes the LES. Frequent sucking on a cigarette can also make you swallow air, which raises stomach pressure and encourages reflux. People who smoke a pack or more a day are the most likely to have symptoms.
Foods and drinks. Diet can undermine the LES. Alcohol can loosen it (and irritate the esophageal lining), as can coffee and other caffeine-containing products. Coffee, tea, cocoa, and cola drinks all strongly stimulate gastric acid production. Mints and chocolate - often offered after a meal to aid digestion - can relax the LES and trigger heartburn. Some people blame onions and garlic; others struggle with citrus fruits or tomato products, which can irritate the esophageal lining. High-fat and fried foods can set off symptoms as well. If you notice a particular food leads to heartburn episodes, by all means steer clear of it.
Eating patterns. How you eat matters as much as what you eat. Skipping meals and then eating heavily raises pressure inside the stomach and the likelihood of reflux. Lying down right after a meal only makes things worse. It is best to wait three hours after eating before going to bed - and to skip late-night snacks.
Medications. Some prescription drugs can aggravate heartburn. Oral contraceptives and postmenopausal hormone preparations containing progesterone are known culprits. Aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and naproxen can also cause problems. Corticosteroids can bring on heartburn too. Osteoporosis drugs such as alendronate irritate the esophagus. And certain antidepressants, tranquilizers, and calcium-channel blockers (used for high blood pressure or coronary artery disease) can contribute to reflux by relaxing the LES.
To keep pills from irritating your esophagus, take a few sips of water before swallowing and drink a cup of liquid afterward to speed the pill's passage into your stomach. If you take any drug known to irritate the esophagus, such as alendronate, remain standing or sitting upright for at least 30 minutes after each dose.
Hiatal hernia. A hiatal hernia is a common condition that develops when part of the stomach pushes up through the diaphragm, the sheet of muscle separating the chest from the abdomen that aids breathing. The diaphragm has a small opening (the hiatus) that should be just wide enough for the esophagus to pass through. With a hiatal hernia, part of the stomach also protrudes through the diaphragm into the chest, which can impair the LES's ability to block reflux.
