Asthma & Obesity: Why Treating Both Matters

By Ankit Kushwaha, MD, FACP 

Summer 2026

 

Asthma and obesity are two of the most common chronic diseases in the United States. On their own, each can affect breathing, activity level and overall quality of life. But when they occur together — as they often do — they can create a cycle that makes both conditions harder to control.

Doctors are increasingly recognizing that asthma and obesity are closely linked. Treating one without addressing the other may leave patients struggling with persistent symptoms, frequent flare-ups and avoidable hospital visits.

A Complicated Pairing

Asthma affects millions of Americans, causing inflammation and narrowing of the airways. People with asthma may experience wheezing, chest tightness, shortness of breath and coughing, especially at night or with exercise.

While obesity is already known to be associated with diabetes, heart disease and sleep disorders, its effect on the lungs is not as commonly known to the public.

The relationship between asthma and obesity can be described in three different ways. First, obesity can cause asthma to develop, especially in people who develop asthma later in life, most commonly in their 40s. Second, asthma can promote or contribute to weight gain by either limiting physical activity or as a side effect of oral steroids, which are commonly used medications when asthma symptoms are flaring. Third, patients living with asthma and obesity may find that as excess weight increases, asthma symptoms become harder to control, causing them to use more medications to maintain symptom control.

Research suggests that obesity is associated with an increased risk of developing asthma.

Asthma is a complex condition influenced by many factors including genetics, allergies, environment, infections and overall health. While obesity can worsen asthma symptoms for some people, not every person with asthma has obesity, and not every breathing symptom is caused by weight alone.

Why Excess Weight Affects Breathing

The connection between obesity and asthma is not just about the extra pounds. Several biological and mechanical factors are at play.

First, excess abdominal weight presses against the diaphragm, the large muscle under the lungs that helps you breathe, and the chest wall. This reduces the amount of air the lungs can hold, especially when lying down, and can make breathing feel more difficult. Airways may narrow more easily at lower lung volumes, increasing wheezing and shortness of breath.

Second, obesity is associated with chronic low-grade inflammation throughout the body. Body fat tissue releases inflammatory substances that can affect the lungs and potentially worsen airway inflammation. Over time, this may reduce the effectiveness of asthma inhalers.

Third, obesity often brings additional conditions — such as gastroesophageal reflux disease (GERD or acid reflux) and obstructive sleep apnea — that can aggravate asthma symptoms.

Harder-to-Control Asthma

The combination of asthma and obesity can be extremely frustrating for patients. They may take their inhalers regularly yet continue to feel short of breath. They may wake up at night coughing or struggle with exercise that once felt manageable.

It can feel as though they are caught in a frustrating cycle because their inhalers seem less effective, leading to more frequent prescriptions for oral steroids. While these medications can provide short-term relief, they may also contribute to weight gain, which can make asthma symptoms harder to manage over time.

Not All Breathing Problems Are Asthma

It is important to recognize that shortness of breath in people with obesity is not always due to asthma alone. Reduced fitness, loss of fitness from reduced physical activity and the mechanical effects of excess weight can mimic asthma symptoms.

That is why objective testing, such as a pulmonary function test (PFT), is essential to confirm the diagnosis of asthma and guide treatment. Unfortunately, almost one-third of patients who are labeled as having asthma do not have evidence of it on PFTs.

It can be valuable to determine that a patient may not actually have asthma and can safely discontinue daily inhaler therapy when appropriate. However, determining that a patient may not actually have asthma does not mean their breathing symptoms are not real. Addressing overall health, including obesity and related conditions, may still help improve breathing and quality of life.

Paths to Better Asthma Control 

The encouraging news is that even modest reductions in body weight can improve asthma outcomes. Research has shown that losing as little as 5% to 10% of body weight can lead to better asthma control, fewer symptoms and an improved quality of life. Many patients also report needing their rescue inhaler less often and experiencing fewer nighttime symptoms and sleep disruptions. 

In individuals who undergo bariatric surgery, improvements can be even more striking, with reductions in asthma severity and medication use. However, surgery is not necessary for most people to see benefits. Structured lifestyle programs combining dietary changes and physical activity can make a meaningful difference.

Experts emphasize that exercise alone is usually not enough to produce significant weight loss. However, regular physical activity still provides important benefits for overall health, breathing, energy levels and quality of life regardless of weight changes. Sustainable results typically require a comprehensive approach that includes nutrition, physical activity, behavioral strategies and, in some cases, anti-obesity medications.

Researchers continue to learn more about the health benefits of GLP-1 medications, including improvements in heart disease, diabetes, kidney disease and liver disease. While no randomized controlled trial (RCT) has been done specifically for GLP-1 medications in asthma, researchers have found observational data — meaning patterns seen in real-world patients rather than formal clinical trials — showing reduced risk of asthma flare-ups and improved quality of life in patients with asthma and obesity after starting GLP-1 medications.

Treating obesity should not replace standard asthma therapy. Inhaled corticosteroids and other daily long-term asthma medications remain the foundation of asthma care. But addressing weight as part of the overall plan can make these treatments more effective.

The Role of Obstructive Sleep Apnea

Another important, and often overlooked, link between asthma and obesity is obstructive sleep apnea (OSA). OSA is a condition in which the upper airway repeatedly collapses during sleep, causing pauses in breathing, drops in oxygen levels, snoring and disrupted sleep. It is strongly associated with obesity and becomes more common as body weight increases.

People with asthma are more likely to have OSA than the general population. Among adults with asthma, the prevalence of sleep apnea may approach 40% to 50%. When asthma and OSA occur together, each condition can make the other more difficult to manage. Individuals with both asthma and untreated OSA often report more severe symptoms, more frequent flare-ups and a lower quality of life compared with those who have asthma alone.

Fortunately, treating OSA can improve more than just sleep quality. Whether through CPAP (continuous positive airway pressure) therapy, weight-management strategies or other appropriate treatments, addressing OSA may also help improve asthma control and overall well-being.

A Holistic Approach to Care

The growing understanding of the connection between asthma, obesity and sleep apnea has changed how clinicians approach difficult-to-control asthma. Rather than simply increasing inhaler doses, many specialists now take a broader view. They assess related health conditions such as obesity, obstructive sleep apnea (OSA), gastroesophageal reflux disease (GERD), anxiety and depression, all of which can influence asthma symptoms.

This “treatable traits” approach recognizes that asthma is not simply an isolated airway disease. It is often part of a larger health picture. Addressing each contributing factor may improve outcomes more effectively than focusing on the lungs alone. For patients, this means conversations about nutrition, physical activity, sleep quality and weight can be just as important as proper inhaler use.

What Patients Can Do

For individuals living with both asthma and obesity, small, steady steps can make a meaningful difference:

• Work with a healthcare team to confirm the asthma diagnosis and optimize inhaler use.
• Ask about screening for sleep apnea if there is loud snoring, daytime sleepiness or frequent nighttime awakenings.
• Set realistic weight-loss goals. Even a 5% to 10% reduction in body weight can improve breathing.
• Focus on sustainable dietary changes rather than extreme or short-term diets.
• Incorporate regular, moderate physical activity as tolerated, with guidance from a clinician if needed.
• Prioritize healthy sleep habits and consistent use of CPAP if prescribed.

Understanding the Bigger Picture

Asthma is a complex condition influenced by many factors including genetics, allergies, environment and overall health. For some individuals, obesity and related conditions such as obstructive sleep apnea may contribute to worsening symptoms and reduced quality of life.

Addressing factors such as sleep, physical activity and overall health may help patients improve breathing, sleep better and experience a better quality of life.

 

About the Author: 

Ankit Kushwaha, MD, FACP, is a dual board-certified physician in pulmonary and obesity medicine in Jackson, Tennessee. He established the first combined asthma and obesity clinic in the U.S. after recognizing the impact obesity can have on respiratory health and the need for greater access to evidence-based obesity care in West Tennessee.