Breathing Difficulties

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder in which the gradual death of nerve cells in the brain results in a progressive weakening of muscles throughout the body.

While the symptoms of ALS often vary among patients, breathing problems will at some point confront all of them.

When the muscles involved in breathing weaken, it becomes difficult to inhale and exhale, and a person begins to take shorter and shallower breaths. This causes less oxygen to enter the blood and less carbon dioxide to be released, potentially leading to poor or restless sleep, fatigue, and headaches. Weakened respiratory muscles can also make it difficult to cough with sufficient force to clear airways, allowing infections, such as bronchitis, to set in. Such infections can be serious if not treated quickly.

Monitoring breathing capacity

The loss muscle strength is very gradual in ALS, so it is important to closely monitor a person’s breathing in order to notice and act on the signs of difficultly quickly. Early symptoms include frequent shortness of breath and trouble sleeping. Once these signs are evident, a respiratory specialist should be consulted to assess whether the breathing muscles have begun to weaken.

variety of tests exist to measure breathing function. They include a “vital capacity” (VC) test, where the patient blows into a device called a spirometer, that checks the amount of air expelled after a full inhalation.

A maximum inspiratory pressure (MIP) test can also be used to measure the strength of the breathing muscles when inhaling. This is also referred to as maximum inspiratory force (MIF). This test can also be repeated for exhaling, in which case it is called a maximum expiratory pressure (MEP) test.

Finally, the level of oxygen in the blood can be measured noninvasively by an oximeter (a small sensor placed on the pulse point).

Help for breathing problems


Respiratory specialists and physiotherapists can provide advice on techniques and exercises to maximize breathing capacity and improve the ability to cough. These exercises help to keep ALS patients independent for as long as possible.

Ventilation aids

Ventilation (use of a machine to increase air flow in the lungs) is an option as the disease progresses, and its use will be undertaken in consultation with respiratory professionals. Ventilation can be non-invasive or invasive (i.e. tracheostomy).

Non-invasive ventilation is the most common form of ventilation used. It aids breathing using a portable machine with a nose or face mask. This is also referred to as non-invasive positive pressure ventilation. Initially, it is used during the night to help ALS patients breathe easily while asleep or at rest, but its use can extend to daytime hours as well.

A tracheostomy is a surgical procedure that involves a tube being inserted into the windpipe through the neck, that is then connected to a machine which either supports or takes over the breathing process.

Other information

It is essential to be on guard for signs of respiratory infections, such as a fever, changes in the color or consistency of phlegm (the fluid that can be produced when coughing), or a sudden change in breathing ability so that a patient can be treated appropriately and quickly.

ALS News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.