Dealing with uncontrolled asthma can be frustrating, especially when your inhaler doesn’t seem to make a difference. The underlying cause could be acid reflux. Gastroesophageal reflux disease (GERD) occurs when acid reflux is persistent. As the acid rises up the oesophagus, it can irritate the airway, causing breathing difficulties.

Up to 75% of patients with “difficult to treat asthma” also experience acid reflux symptoms like heartburn. But what most patients don’t realise is that coughing, wheezing, chest tightness, and breathlessness can all be linked to acid reflux.

Below, we’re exploring the connection between acid reflux disorder and asthma symptoms, including why it happens, common triggers, and what you can do about it.

How Acid Reflux Can Trigger Asthma Symptoms

Asthma is an inflammatory condition where the airways narrow due to triggers. As the airway tightens, people experience wheezing, shortness of breath, and coughing. The underlying trigger can vary widely from person to person.

Usually, people consider triggers like dust or cold air. But acid reflux could be another factor. Acid from the stomach can irritate the oesophagus and airways. Even small amounts of reflux reaching the upper airway (sometimes called micro-aspiration) may contribute to airway irritation and inflammation. The vagal nerve is then activated (which lies next to the oesophagus) and triggers airway tightening.

A common pattern is worsening asthma symptoms at night or when lying down. That’s because acid reflux often occurs after a large evening meal or moves readily up the oesophagus when you lie flat.

Why Asthma Can Make Reflux Worse (It Works Both Ways)

Asthma also has an effect on GERD.

Coughing increases chest pressure and squeezes the stomach. Combined with chest tightness, this pushes acid up the oesophagus, causing minor acid reflux.

Inhalers and asthma medications may relax the lower oesophageal sphincter (LOS) in certain people, potentially increasing the chance of reflux.

Symptoms That Overlap (and Cause Confusion)

Not everyone with asthma symptoms from acid reflux has asthma, nor do all people with occasional acid reflux due to asthma have GERD. These conditions often overlap. It’s not obvious what’s driving the symptoms: breathing or stomach.

• Common shared symptoms include:

• Chronic cough, especially at night or after meals

• Chest tightness, which may feel respiratory or oesophageal

• Shortness of breath, particularly when lying down

• Hoarseness or throat irritation, often worse in the morning

Because these symptoms appear in both conditions, acid reflux and asthma symptoms are frequently treated in isolation, even though they might actually be connected.

Common Triggers That Aggravate Both Conditions

Another common confusion is triggers. Certain triggers can irritate airways, increase inflammation, and allow acid to travel upward.

Common triggers include:

• Acidic, fatty, or spicy foods. These foods characteristically stimulate acid production, triggering reflux. But fatty or ultra-processed foods also increase bodily inflammation, increasing the risk of an acid attack.

• Alcohol and caffeine. Drinking alcoholic or caffeinated beverages relaxes the lower oesophageal sphincter and stimulates acid production. Alcohol can trigger airway narrowing. It also causes dehydration, which thickens mucus, making it harder to clear.

• Poor sleep and stress. These factors make everything worse. They trigger inflammation and can increase symptom sensitivity.

• Lying flat at night. When you lie flat, it’s easier for acid to reach the upper airway. Micro-aspirations can occur more commonly at night.

Why Treating Reflux Can Improve Asthma Control

If you’re dealing with uncontrolled asthma symptoms, getting on top of acid reflux is a sensible solution. Even if you don’t have heartburn, silent reflux (or laryngo-oesophageal reflux (LPR)) can cause acid reflux without you realising it.

Most people notice that with a few changes, they can reduce airway irritation, have fewer nighttime symptoms, and improve their response to asthma medications.

Here are a few tips:

Lifestyle changes:

• Reducing portion size and eating earlier before bedtime can decrease the chance of acid reflux at night.

• Avoid triggers like fatty meals, alcohol, and acidic foods.

• Prop yourself up in bed, so you’re not lying flat.

Manage reflux triggers. If you’re drinking alcohol, not getting enough sleep, or feeling stressed, both acid reflux and asthma symptoms can get out of control. Focus on getting enough sleep and managing stress, as they can act as persistent low-level triggers.

Coordinate asthma and reflux care. Don’t treat each condition in isolation. If necessary, use an acid reflux medication (e.g., a PPI or H2 blocker) to see whether reflux is contributing to asthma symptoms. It can provide temporary relief to allow your asthma to get under control. Never stop or change asthma medications without speaking to a healthcare professional first.

Still Struggling to Control Your Asthma?

If asthma symptoms persist despite treatment, acid reflux (including silent reflux) may be playing a role. The Functional Gut Clinic offers a range of diagnostic testing options to confirm, or exclude, the presence of acid reflux.

Learn more about our GERD diagnostic process and how it could help you relieve airway irritation and improve asthma control.

We recommend this related article: Heartburn and Heart Attack: What’s the Difference?