What You Need to Know About Respiratory Muscle Weakness

Respiratory muscle weakness is a common disorder often associated with weakened coughing, breathing and other airway functions, and providers and patients must know how to identify symptoms of this condition to ensure the healthiest breathing and respiratory functions possible. 

What is Respiratory Muscle Weakness?

Respiratory muscle weakness can occur when someone has developed a neuromuscular disease, and the symptoms are often only apparent when the condition is severe. As your muscles break down, the breathing muscles, otherwise known as the diaphragm and intercostal muscles, can begin to break down as well. This makes the process of taking in oxygen and releasing carbon dioxide waste extremely difficult.

The number one cause of death for those living with neuromuscular disease is weak breathing muscles, meaning some of these symptoms are fatal.

Mucus Plugging from respiratory muscle weakness

Many times, it’s impossible for individuals to clear lung secretions, such as mucus, when suffering from respiratory muscle weakness, which can lead to emergencies and airway suctioning. If the airway isn’t suctioned in time, muscle weakness can result in mucus plugging, causing respiratory infections and even pneumonia.

Sleep-disordered breathing

In the early stages of neuromuscular disease, many people find themselves waking up frequently throughout the night or experiencing morning headaches that go away after a few minutes of being awake. These symptoms are associated with sleep-disordered breathing, which causes a person to breathe shallowly and experience fatigue or drowsiness during the day.

Predisposition to Neuromuscular Disease

Breathing problems are most likely the cause of one or more underlying respiratory issues. Some reasons why a person may be experiencing breathing problems and neuromuscular weakness associated with neuromuscular disease include:

• The person may have a naturally smaller lung volume, leaving the chest with less room to expand.
• The respiratory muscles have been weakened to the point of being unable to produce a cough strong enough to clear the throat.
• A person may have weaker throat muscles that causes them to swallow food abnormally.
• The individual suffers from scoliosis or another disease that causes physical changes to the body’s structure. This may allow the body to grow in a way that doesn’t leave enough room for the lungs to grow.
  
  

How symptoms vary

There are multiple symptoms associated with respiratory muscle weakness due to neuromuscular disease. The main signs to look for include:

• Inadequate ventilation during sleep.
• Nocturnal hypoventilation (choking during sleep, morning headaches, impaired cognition and fatigue).
• Awake hypoventilation, which can manifest as improper ventilation during the time someone is awake.
  
  

These symptoms can occur for different lengths of time as well:

• Acute duration often occurs in patients with spinal cord or nerve trauma.
• Chronic duration can present itself slowly over the course of a few months due to other issues like multiple sclerosis or spinal cord tumors.
• Relapses can be a common occurrence for patients with multiple sclerosis.
• Acute-on-chronic can be seen in patients with a chronic neuromuscular disorder. These individuals may develop complications such as aspiration pneumonia.
• Progressive disorders may be identified, such as ALS, spinal muscular atrophy, post-polio syndrome and syringomyelia.
  

Recognize and Address Respiratory Muscle Weakness

Respiratory muscle weakness is a serious condition often linked to neuromuscular diseases, and it can significantly impact a person's ability to breathe effectively. Recognizing the symptoms early is crucial for timely intervention and management.

Healthcare providers and patients must work together to identify these signs and implement appropriate treatments to maintain optimal respiratory function. Understanding the underlying causes, such as structural changes or reduced lung volume, can also aid in developing personalized care plans. By staying informed and vigilant, individuals with neuromuscular diseases can improve their quality of life and reduce the risk of severe respiratory complications.

Editor's note: This blog was originally from October, 2023. It has been re-published with additional up to date content.