Respiratory Testing
MIP and MEP Tests
Maximal inspiratory pressure and maximal expiratory pressure testing
At a Glance
- MIP and MEP tests measure the strength of your breathing muscles.
- They are different from spirometry, which measures air volume and flow rather than muscle strength.
- Your doctor may order this test if you have unexplained breathlessness, a weak cough, or a condition that can affect muscle strength.
- The test is quick, non-invasive, and does not involve needles or radiation.
- Not sure why you have been referred? Read this article to understand what the test involves and what your results mean.
About the Test
What are MIP and MEP tests?
MIP - breathing in
MIP is a global measure of inspiratory muscle strength, primarily assessing the diaphragm. It measures the maximum pressure you can generate when inhaling against resistance, reflecting the strength of your diaphragm and the muscles between your ribs, and helps evaluate for ventilatory failure and lung disease.
MEP - breathing out
The MEP test measures the maximum pressure you can create when exhaling forcefully, reflecting the strength of your abdominal and chest wall muscles.
What to Expect
How do MIP and MEP tests work?
The MIP and MEP tests use our standard testing equipment to measure the air pressure your breathing muscles can generate. You breathe through a mouthpiece connected to the equipment, and the pressure from each effort is recorded. A nose clip is worn throughout to prevent air from escaping through the nose.
MIP: Breathing in
Breathe out as fully as you can, then inhale as hard and fast as possible into the mouthpiece for at least one second.
MEP: Breathing out
Breathe in as deeply as you can, then blow out as forcefully as possible into the mouthpiece.
Each manoeuvre is repeated several times to ensure consistent, reliable results. The test is effort-dependent, meaning your results reflect the effort you apply. Your respiratory technician will coach you through each step to help you get the most accurate reading.
Why It Is Requested
Why might your doctor order MIP and MEP testing?
Symptoms we may investigate
- Unexplained breathlessness, particularly when lying flat
- A weak or ineffective cough
- Breathing difficulties that are not fully explained by spirometry results
- Fatigue that worsens with physical activity
- A condition known to affect muscle strength
Conditions that may need monitoring
- COPD (chronic obstructive pulmonary disease)
- Motor neurone disease (MND)
- Muscular dystrophy and other neuromuscular conditions
- Diaphragm weakness or dysfunction
- Myasthenia gravis
- Post-COVID breathlessness (long COVID)
- Sleep apnoea
Your GP or specialist may refer you for MIP and MEP testing to investigate symptoms or monitor a condition that can affect breathing-muscle strength.
Appointment Details
What you need to know
Allow 45–60 minutes
This test typically takes 45–60 minutes.
Results in 1–2 business days
Results are shared with your referring doctor within 1–2 business days.
Preparing for Your Test
How to prepare
Medical documents
Bring your referral letter and any other documents or test results that may be important for the specialist to consider.
Clothing
Wear comfortable, loose-fitting clothing that does not restrict your chest or abdomen.
Medications
Ask your specialist if you can continue your existing medications. If the test is ordered alongside spirometry or bronchodilator testing, you may be asked to pause certain inhalers.
Special considerations
Let your technician know if you have experienced recent chest pain, recent eye or abdominal surgery, or any condition that may affect your ability to perform a forceful breathing effort.
Food and drink
Avoid eating a large meal within 2 hours of the test and do not drink alcohol for at least 4 hours beforehand.
Smoking
Do not smoke on the day of the test.
Exercise
Do not engage in heavy exercise for at least 1 hour before the test.
- The test is not painful.
- Each effort requires a short burst of maximal force, similar to blowing up a balloon as hard as you can.
- Mild lightheadedness afterwards is common and settles quickly.
- Rest time is given between each effort.
- The full appointment, including preparation and rest breaks, typically takes 45 to 60 minutes.
Your results show how strong your breathing muscles are, measured in cmH₂O (centimetres of water pressure). Think of it like a grip-strength test, but for your lungs. Your specialist will compare your results against established reference values for people of your age, sex and height.
A result below the expected range may suggest your breathing muscles are not generating as much pressure as anticipated. This does not automatically mean something is seriously wrong.
Your specialist will interpret your results alongside your symptoms, medical history and other lung-function tests, never in isolation.
Helpful Information
Frequently asked questions
Can I still take the test if I have a cold or chest infection?
If you are currently unwell with a respiratory illness such as a cold, flu or chest infection, it is best to contact the clinic before your appointment.
Active illness can affect your ability to perform the breathing manoeuvres to your full capacity, which may mean your results do not accurately reflect your true muscle strength. The clinic may recommend rescheduling until you have recovered.
Is there anything that could make the test invalid?
Yes. Several factors can affect the quality or reliability of the results:
- Effort: Inconsistent attempts may need to be repeated until reliable readings are obtained.
- Air leaks: A poor seal around the mouthpiece can lead to inaccurate readings.
- Recent illness: A respiratory infection may reduce your maximum effort.
- Pain or recent surgery: Recent chest, abdominal or eye surgery may limit how forcefully you can breathe.
Your respiratory technician will assess the consistency of your results and repeat efforts as needed.
Is this service bulk-billed?
MIP and MEP testing may be bulk billed for eligible patients at our Sunshine clinic.
Service locations
- Ballarat
- Sunshine
- Warrnambool
Bulk billing
MIP and MEP testing may be bulk billed for eligible patients at our Sunshine clinic.
Ready to Book?
Have you been referred for MIP and MEP testing?
Our respiratory testing team can help you arrange your appointment and understand what to expect.