Understanding Respiratory Health in Duchenne Muscular Dystrophy

The body’s respiratory muscles—the muscles that give us the ability to breathe—play an important role in DMD.

Why Respiratory Muscles Matter

Leg and heart muscles get much of the early attention in DMD, but as the disease progresses, the respiratory muscles also begin to weaken. This can cause difficulties with breathing and coughing.

Eventually, these weakened muscles can cause serious health problems. In fact, respiratory issues are a leading cause of death among those with DMD.

But there are ways to manage the respiratory risks those with DMD face, including breathing support and airway clearance. This site is here to help you understand the potential respiratory concerns in DMD, to help you understand these options, and to help make sure you or your loved one are getting the best care possible.

Knowing more about respiratory health can help you be an advocate for those with DMD and have meaningful conversations with your healthcare provider about caring for those with DMD.

Download a guide to respiratory health for more information about the role of respiratory muscles in DMD.

Stages of DMD and Respiratory Health

The impact grows as time goes on.

DMD can affect respiratory health in various ways. In the early stages, these effects can be subtle, but with time become more pronounced.

stethoscope on top of the right lung


At diagnosis most boys with DMD breathe normally and have normal respiratory function.

high-top sneakers with laces


As long as boys with DMD are able to walk, they are less likely to have serious respiratory problems. Even so, it’s wise to understand respiratory health and to get a baseline measurement of lung function at this stage. Lung function testing measures the strength of the lungs and their ability to inhale and exhale properly. The measurements from that test can be used by you and your doctors and nurses to better understand changes in lung function down the road. View respiratory monitoring.

wheelchair with two wheels and a arm rest

Early non-ambulatory

Once a boy or man starts to use a wheelchair, the risk for respiratory issues increases. Early signs that the respiratory muscles are weakening—like headaches, fatigue, and restless sleep—aren’t always obvious. Learn more about these early respiratory symptoms.

wheelchair to represent adults

Late non-ambulatory

People living with DMD have a higher risk of facing a range of respiratory problems. Read about some of the later symptoms they may face.

There is help for when these symptoms escalate. Read about the importance of keeping the airway clear.

About Respiratory Muscles in DMD

Muscles make breathing possible.

It’s important to understand the role that these muscles play and what they mean for DMD.

The lungs can’t breathe on their own. They need the coordinated movement of a collection of the muscles. The muscles help expand and contract to move air in and out of the body.

  respiratory muscles
  respiratory muscles
curvature of the spinal cord to show Scoliosis


Scoliosis — when the spine is curved sideways — can make it harder for weakened lungs to do their job properly.

Once those with DMD begin to use a wheelchair, some will develop scoliosis, which changes their posture.

This altered posture affects the movement of the ribs during the breathing process and alters the shape of the chest cavity, which makes it harder to breathe.

Read about the importance of respiratory monitoring and respiratory devices to improve breathing.

Early Respiratory Symptoms in DMD

Boys with DMD may begin to experience subtle respiratory symptoms once they start using a wheelchair.

high-top sneakers with laces


As long as boys with DMD can walk, they are less likely to have serious respiratory complications.

But it’s important to understand how even early respiratory changes can lead to more serious respiratory problems and what options may be available.

wheelchair with two wheels and a arm rest


Once a boy with DMD becomes non‑ambulatory, there may be signs that the respiratory muscles are weakening.


Early signs include:

Restless sleep
Difficulty concentrating
Not feeling rested
Difficulty staying awake

Respiratory muscles weaken over time. In the first few years of wheelchair use, the first signs of declining respiratory muscles don’t appear to be tied to the lungs.

Learn more about how to help improve well-being when living with DMD.

Later DMD Respiratory Symptoms

Eventually respiratory-related symptoms begin to show. These symptoms can be subtle—like not being able to cough hard enough—but may grow more serious.

Ineffective Cough

Think of coughing as the body’s way of clearing the airways. When mucus and other secretions build up, coughing helps remove them. The stronger and more forceful the cough, the more effective it is at keeping the airway clear of secretions.

So what makes a strong cough? Strong muscles. When the muscles weaken, the lungs can’t take in as much air as they should. Weakened muscles also can’t create a cough strong enough to clear the airway. And that can lead to infections, which tend to last longer in people with DMD because of their weaker muscles. The weaker the muscles get, the more they need help.

But there are ways you can manage a weak cough, like using cough assist devices or manual cough techniques.

Read about cough assistance devices and physical assistance techniques to clear airways.

Sleep-Disordered Breathing

Sleep-disordered breathing occurs when there are sleep problems because of abnormal breathing patterns.

Disrupted sleep impacts the ability to think, how the body grows, and quality of life. And because of their weakened respiratory muscles, people with DMD might be more prone to sleep problems. Lying flat on the back makes the abdominal contents move upward against the diaphragm, which makes the already weakened muscle work harder.

  Obstructive Sleep Apnea (OSA)  Shallow Breathing at Night

How do you know if someone has difficulty breathing at night?

There are tests boys and men can take to gauge their level of disrupted breathing.

Read about the tests and what they measure in respiratory monitoring.

Atelectasis (pronunciation: Aht-ell-lect-tuh-sis)

This occurs when a part of the lung “collapses” and doesn’t properly inflate. If only a small part of the lung collapses in those with DMD, they might not have any signs or symptoms.

For people with DMD, a partial collapse in the lungs can occur when airways in the lungs become blocked, typically with mucus, and the cough is not strong enough to clear the airway. A blocked airway means air sacs (called alveoli) in the lungs don’t inflate properly and thus they shrink and collapse. You might hear people refer to this partial collapse as atelectasis.

Besides a mucus blockage, another cause of atelectasis is when the lungs don’t fully expand and fill with as much air as they should. Shallow breathing can cause this type of atelectasis.

Partially collapsed lung

What can help prevent air sacs from collapsing? If mucus is blocking an airway, a mechanical suction device can remove it. Your doctor might prescribe medicines or advise physical techniques like chest clapping to help loosen mucus.

Cough assist devices can be used to help a patient breathe in deeply and then breathe out forcefully, very much like a cough.

Learn about ventilation devices and cough assist techniques to prevent mucus build up in the lungs.

Daytime Levels of Oxygen and Carbon Dioxide

Weakened breathing muscles mean the levels of oxygen and carbon dioxide in your blood start to shift in ways that aren’t good for the body. Initially this shift in levels happens at night. But as the respiratory muscles continue to weaken, reduced levels of oxygen (caused by shallow breathing) and high levels of carbon dioxide (known as hypercapnia) show up during the day.

Read about how ventilation devices might be able to help and about how to manage medical issues in DMD.

Severe Respiratory Difficulty

The continual weakening of the respiratory muscles makes it harder for the lungs to take in enough oxygen and get rid of enough carbon dioxide, so people with DMD might need increasing levels of support to breathe.

When it comes to breathing assistance, you have options and ways to support your loved one.

Read about ventilation devices.