When muscle weakness affects breathing

If the muscles you use to breathe are weak, your breathing may become shallow. This is called hypoventilation. Curves in the spine and heart problems can also affect your breathing.

Weakness in these muscles can make it hard to cough up mucus from your airway. This can make breathing harder and lead to chest infections.

The lungs pass oxygen into the blood and remove carbon dioxide. If you have hypoventilation, too much carbon dioxide stays in your blood, and you may not get enough oxygen. This can cause symptoms such as:

• Breathlessness
• Disturbed sleep
• Tiredness, fatigue (extreme tiredness), and sleepiness
• Waking up with a headache
• Finding it hard to concentrate
• Poor appetite

Many people first notice symptoms at nighttime. Symptoms during the day can develop gradually and be hard to notice.

Young children or people who cannot communicate their symptoms may show changes in their behaviour.

Weight loss can also be a sign of weakness in the chest muscles. We use the muscles in our chest and neck to swallow. If they’re weakened, it can be difficult or tiring to eat. As a result, people may eat less, leading to weight loss.

Your healthcare team should check your breathing at your routine appointments. You may not notice any symptoms at first, but regular checks can pick up changes early. It’s important to tell your GP or healthcare team if you have any symptoms.

If there are signs of a breathing problem, your GP or healthcare team may refer you to a specialist ventilation service. This is a team that usually includes respiratory (breathing) doctors, nurses, and physiotherapists. If you have trouble swallowing, they may also refer you to a speech and language therapist.

You may have regular appointments with the ventilation service to check your breathing. How often you have these appointments will depend on your symptoms and muscle wasting condition.

At your appointments, you may have some tests to check your breathing and measure the strength of your breathing muscles.

Your healthcare team will ask you about your general health and any breathing symptoms. They may offer you some tests to see how the muscles you use for breathing and lungs are working. They may offer you these tests regularly to look for any changes in your breathing.

Spirometry

You may have tests to measure how much air you breathe in and out. This is called spirometry.

A common spirometry test is the forced vital capacity (FVC) test. It measures how much air you can blow out in one breath. You take a deep breath in and blow into a mouthpiece as hard and fast as you can.

Muscle strength

You may have a test to measure how strong your breathing muscles are. Possible tests include:

• Maximal inspiratory pressure (MIP) – to check the strength of the muscles you use to breathe in through your mouth.
• Maximal expiratory pressure (MEP) – to check the strength of the muscles you use to breathe out through your mouth.
• Sniff nasal inspiratory pressure (SNIP) – to check the strength of the muscles you use to sniff and breathe in through your nose.

For the MIP and MEP tests, you will need to form a seal with your mouth around a mouthpiece or use a mask. If you find this difficult, you may have the SNIP test. This involves placing a probe just inside the nose to measure muscle strength when you sniff.

Cough strength

Your healthcare team may check whether your cough is strong enough to clear mucus from your chest. A peak cough flow (PCF) test involves coughing as hard as you can into a mouthpiece or face mask. This is attached to a meter, which measures the strength of the cough.

Sleep studies

Sleep study tests aim to measure your breathing during sleep. They can help find problems before they happen during the day. Your healthcare team will talk to you about which test you may have. Possible tests include:

• Pulse oximetry – this measures your oxygen levels and heart rate throughout the night. You can have this test at home, wearing a monitor on your wrist and a probe on your finger.
• Transcutaneous carbon dioxide level – you may have this test in hospital, or sometimes at home. A sensor measures oxygen and carbon dioxide levels through a probe attached to your skin. It’s attached to a monitor that sits next to the bed.
• Multichannel sleep studies – there are a range of devices to measure breathing during sleep. These may use bands around the chest, a tube under the nose, a probe or ring attached to the finger, or patches on the skin. You can use these at home.
• More detailed sleep study (respiratory polygraphy) – you may need a more in-depth sleep study to look at your breathing effort and pattern. For example, if other tests show possible breathing problems. You may have this test in hospital.

Breathing support and exercises can help keep the lungs clear and make breathing easier. Your healthcare team will help you choose a treatment that works for you.

Non-invasive ventilation

If you have hypoventilation, a breathing machine can help you breathe and relieve any symptoms. This is called non-invasive ventilation (NIV). Most people start by using this at night. You can also use it during the day if the muscles you use for breathing get weaker. NIV does not make your condition worse.

Your healthcare team will give you a mask attached to a breathing machine. The machine increases the air pressure to open your lungs. This helps you breathe. There’s a range of masks available, and you can use different masks for night and day. Your healthcare team will see which masks work best for you, and which you like most. You can also buy masks online but check with your healthcare team that they will work with your machine.

Using a breathing machine should not stop you from doing your usual daily activities. Many people go on holiday and travel abroad with their machines. Your healthcare team can give you advice about this. You may need some tests first to make sure it’s safe for you to fly.

Invasive ventilation

Invasive ventilation is also called tracheostomy ventilation. A tube is placed through the front of the neck into the windpipe. The breathing machine is connected to this tube.

You may need a tracheostomy if your condition is getting worse, you’re getting lots of chest infections, or you’re not able to use NIV. Some people need invasive ventilation in hospital after a period of severe illness.

Managing a weak cough

If you have a weak cough, your healthcare team will look at ways of making it stronger. You will usually see a specialist physiotherapist for this. They may suggest:

• Breath-stacking – this involves taking repeated breaths in without breathing out. Once you have filled your lungs with air, you can cough.
• Lung volume recruitment (LVR) – this is a bag that can be attached to a mask, mouthpiece, or tracheostomy. After breathing in fully, you squeeze the bag to push more air into the lungs.
• Manually assisted cough – someone else puts pressure on your tummy area (abdomen) while you cough. This can help make your cough stronger.
• Mechanical insufflation-exsufflation (MI-E), such as Cough Assist – a machine pushes air into your lungs quickly before sucking it back out. This helps you to cough. You can use the machine with a mask, mouthpiece, or tracheostomy.
• Glossopharyngeal breathing – this is not used much now, as it can be hard to learn. It involves taking gulps of air into your lungs to help create a stronger cough. It’s sometimes called frog breathing.

Accidentally breathing in food or drink can cause chest infections. This is called aspiration. If this happens often, you may need to see a speech and language therapist. They can help with swallowing and suggest ways of avoiding aspiration.

Self-care

There are some things you can do to help with breathing problems and lower the chance of getting a chest infection. For example:

• Keeping warm in the colder months
• Being careful around people with coughs and colds
• Getting yearly flu and COVID vaccines

If you have breathing problems, you’re advised to have the pneumococcal vaccine. The RSV vaccine is also recommended for some people. The RSV vaccine protects against the RSV virus, which can cause chest infections, particularly in people with breathing difficulties.

You may want to carry an alert card or a medical alert bracelet. You can also use a built-in health app on your smartphone. This can give useful information about your condition to medical staff, especially in an emergency. You can order or download condition-specific alert cards for some conditions from our alert card page.