- 19 million people in the United States are believed to suffer from GERD
- People of any age, even infants, can get GERD
- 70% of people with asthma have GERD, as opposed to only 20% to 30% of people who don't have asthma
Experts first identified the connection between GERD and asthma in the 1970s, but for decades, studies failed to prove which came first. Did asthma cause GERD? Or did GERD cause asthma? Or did some common factor cause both? A study published in 2008 finally began to shed some light on this connection, which we'll discuss further on.
What Is GERD?
Your esophagus is the tube in your throat that carries food from your mouth into your stomach. Near the bottom of this tube, there's a band of muscle called the lower esophageal sphincter, or LES for short. The LES acts as a kind of valve to regulate the movement of food into and out of the stomach. Normally, it is closed, but in people with GERD, the LES relaxes longer than it should and stomach acid and other contents back up into the esophagus, causing GERD symptoms.
Everyone has the occasional episode of acid reflux, but when it happens more than twice a week every week, you probably have GERD. GERD that is not well-controlled can cause serious complications, including an increase in asthma symptoms.
Symptoms of GERD
GERD symptoms arise mainly from partially digested food and stomach acids backing up into the esophagus, which is extremely irritating and can actually cause tissue damage. Heartburn, a burning sensation in the lower part of the mid-chest, behind your breastbone, is the most common GERD symptom in children over the age of 12 and adults. Younger children often have no heartburn at all. Other symptoms of GERD can include:- Regurgitation (tasting your food after swallowing it)
- Pain or difficulty with swallowing
- Sudden, copious saliva
- Chronic sore throat and / or hoarseness
- Gum inflammation and cavities
- Sour taste
- Bad breath
- Chest pain
Most importantly, for people with asthma, GERD can trigger or worsen asthma symptoms.
What Causes GERD?
Experts aren't sure what causes GERD. Hiatal hernia may be a factor in some people. Clearly, there is some kind of connection with asthma and GERD. Other risk factors appear to be:
- Obesity, also a risk factor for asthma
- Smoking
- Pregnancy
How Does Asthma Affect GERD?
Asthma causes a certain amount of airway obstruction, or blockage. That contributes to asthma symptoms such as chest tightness. It also causes changes in air pressure in your chest that can lead to a relaxing of the sphincter at the bottom of your esophagus that controls the flow of food into your stomach. In other words, negative pressure in your chest actually draws stomach contents up into the esophagus from the stomach.
What Effect Does GERD Have on Asthma?
When asthma causes, or worsens acid reflux, the acid in the esophagus can be aspirated into the airways, which causes further irritability. It may also trigger nerves that interact with the airways, making them narrow.
So, you can see that GERD and asthma work together to worsen symptoms in both directions. Research done with mice at Duke University Medical Center, however, suggests that inhaling the tiny amounts of stomach acid that back up into your esophagus produces changes in your immune system that can lead to the development of asthma. This is the first time scientists have gotten any real clues as to what might be happening in the body to cause such a close connection between GERD and asthma.
Duke researchers agree that more study is needed in order to fully understand the cellular and molecular mechanisms involved in the relationship between GERD and asthma. Still, the study they've already done offers new directions for treating both asthma and GERD.
How Is GERD Diagnosed?
Some definite clues can tell you if GERD and asthma are working together to make your condition worse. Obviously, heartburn is one clue. Others include:
- Asthma symptoms that are worse after meals or exercise
- Nighttime asthma symptoms or heartburn that arises after you lie down
- Frequent coughing and hoarseness
- Recurrent pneumonia
Your doctor can use various tests and scans to help with the diagnosis, as well.
